Given two arrays arr[] and brr[] and an integer C, the task is to find the maximum possible length, say K, of the same indexed subarrays such that the sum of the maximum element in the K-length subarray in brr[] with the product between K and sum of the K-length subarray in arr[] does not exceed C.
Examples:
Input: arr[] = {2, 1, 3, 4, 5}, brr[] = {3, 6, 1, 3, 4}, C = 25
Output: 3
Explanation: Considering the subarrays arr[] = {2, 1, 3} (Sum = 6) and brr[] = {3, 6, 1} (Maximum element = 6), Maximum element + sum * K = 6 + 6 * 3 = 24, which is less than C(= 25).Input: arr[] ={1, 2, 1, 6, 5, 5, 6, 1}, brr[] = {14, 8, 15, 15, 9, 10, 7, 12}, C = 40
Output: 3
Explanation: Considering the subarrays arr[] = {1, 2, 1} (Sum = 4) and brr[] = {14, 8, 15} (Maximum element = 6), Maximum element + sum * K = 15 + 4 * 3 = 27, which is less than C(= 40).
Naive Approach: The simplest approach is to generate all possible subarrays of the two given arrays and consider all similarly indexed subarrays from both the arrays and check for the given condition. Print the maximum length of subarrays satisfying the given conditions.
Time Complexity: O(K*N2)
Auxiliary Space: O(1)
Binary-Search-based Approach: To optimize the above approach, the idea is to use Binary Search to find the possible value of K and to find the sum of each subarray of length K using the Sliding Window Technique. Follow the steps below to solve the problem:
- Build a Segment Tree to find the maximum value among all possible ranges.
- Perform Binary Search over the range [0, N] to find the maximum possible size of the subarray.
- Initialize low as 0 and high as N.
- Find the value of mid as (low + high)/2.
- Check if it is possible to get the maximum size of the subarray as mid or not by checking the given condition. If found to be true, then update the maximum length as mid and low as (mid + 1).
- Otherwise, update high as (mid – 1).
- After completing the above steps, print the value of the maximum length stored.
Below is the implementation of the above approach:
C++14
// C++ program for the above approach #include <bits/stdc++.h> using namespace std; // Stores the segment tree node values int seg[10000]; // Function to find maximum element // in the given range int getMax( int b[], int ss, int se, int qs, int qe, int index) { // If the query is out of bounds if (se < qs || ss > qe) return INT_MIN / 2; // If the segment is completely // inside the query range if (ss >= qs && se <= qe) return seg[index]; // Calculate the mid int mid = ss + (se - ss) / 2; // Return maximum in left & right // of the segment tree recursively return max( getMax(b, ss, mid, qs, qe, 2 * index + 1), getMax(b, mid + 1, se, qs, qe, 2 * index + 2)); } // Function to check if it is possible // to have such a subarray of length K bool possible( int a[], int b[], int n, int c, int k) { int sum = 0; // Check for first window of size K for ( int i = 0; i < k; i++) { sum += a[i]; } // Calculate the total cost and // check if less than equal to c int total_cost = sum * k + getMax( b, 0, n - 1, 0, k - 1, 0); // If it satisfy the condition if (total_cost <= c) return true ; // Find the sum of current subarray // and calculate total cost for ( int i = k; i < n; i++) { // Include the new element // of current subarray sum += a[i]; // Discard the element // of last subarray sum -= a[i - k]; // Calculate total cost // and check <=c total_cost = sum * k + getMax( b, 0, n - 1, i - k + 1, i, 0); // If possible, then // return true if (total_cost <= c) return true ; } // If it is not possible return false ; } // Function to find maximum length // of subarray such that sum of // maximum element in subarray in brr[] and // sum of subarray in arr[] * K is at most C int maxLength( int a[], int b[], int n, int c) { // Base Case if (n == 0) return 0; // Let maximum length be 0 int max_length = 0; int low = 0, high = n; // Perform Binary search while (low <= high) { // Find mid value int mid = low + (high - low) / 2; // Check if the current mid // satisfy the given condition if (possible(a, b, n, c, mid) != false ) { // If yes, then store length max_length = mid; low = mid + 1; } // Otherwise else high = mid - 1; } // Return maximum length stored return max_length; } // Function that builds segment Tree void build( int b[], int index, int s, int e) { // If there is only one element if (s == e) { seg[index] = b[s]; return ; } // Find the value of mid int mid = s + (e - s) / 2; // Build left and right parts // of segment tree recursively build(b, 2 * index + 1, s, mid); build(b, 2 * index + 2, mid + 1, e); // Update the value at current // index seg[index] = max( seg[2 * index + 1], seg[2 * index + 2]); } // Function that initializes the // segment Tree void initialiseSegmentTree( int N) { int seg[4 * N]; } // Driver Code int main() { int A[] = { 1, 2, 1, 6, 5, 5, 6, 1 }; int B[] = { 14, 8, 15, 15, 9, 10, 7, 12 }; int C = 40; int N = sizeof (A) / sizeof (A[0]); // Initialize and Build the // Segment Tree initialiseSegmentTree(N); build(B, 0, 0, N - 1); // Function Call cout << (maxLength(A, B, N, C)); } // This code is contributed by susmitakundugoaldanga |
Java
// Java program for the above approach import java.io.*; import java.util.*; class GFG { // Stores the segment tree node values static int seg[]; // Function to find maximum length // of subarray such that sum of // maximum element in subarray in brr[] and // sum of subarray in arr[] * K is at most C public static int maxLength( int a[], int b[], int n, int c) { // Base Case if (n == 0 ) return 0 ; // Let maximum length be 0 int max_length = 0 ; int low = 0 , high = n; // Perform Binary search while (low <= high) { // Find mid value int mid = low + (high - low) / 2 ; // Check if the current mid // satisfy the given condition if (possible(a, b, n, c, mid)) { // If yes, then store length max_length = mid; low = mid + 1 ; } // Otherwise else high = mid - 1 ; } // Return maximum length stored return max_length; } // Function to check if it is possible // to have such a subarray of length K public static boolean possible( int a[], int b[], int n, int c, int k) { int sum = 0 ; // Check for first window of size K for ( int i = 0 ; i < k; i++) { sum += a[i]; } // Calculate the total cost and // check if less than equal to c int total_cost = sum * k + getMax(b, 0 , n - 1 , 0 , k - 1 , 0 ); // If it satisfy the condition if (total_cost <= c) return true ; // Find the sum of current subarray // and calculate total cost for ( int i = k; i < n; i++) { // Include the new element // of current subarray sum += a[i]; // Discard the element // of last subarray sum -= a[i - k]; // Calculate total cost // and check <=c total_cost = sum * k + getMax(b, 0 , n - 1 , i - k + 1 , i, 0 ); // If possible, then // return true if (total_cost <= c) return true ; } // If it is not possible return false ; } // Function that builds segment Tree public static void build( int b[], int index, int s, int e) { // If there is only one element if (s == e) { seg[index] = b[s]; return ; } // Find the value of mid int mid = s + (e - s) / 2 ; // Build left and right parts // of segment tree recursively build(b, 2 * index + 1 , s, mid); build(b, 2 * index + 2 , mid + 1 , e); // Update the value at current // index seg[index] = Math.max( seg[ 2 * index + 1 ], seg[ 2 * index + 2 ]); } // Function to find maximum element // in the given range public static int getMax( int b[], int ss, int se, int qs, int qe, int index) { // If the query is out of bounds if (se < qs || ss > qe) return Integer.MIN_VALUE / 2 ; // If the segment is completely // inside the query range if (ss >= qs && se <= qe) return seg[index]; // Calculate the mid int mid = ss + (se - ss) / 2 ; // Return maximum in left & right // of the segment tree recursively return Math.max( getMax(b, ss, mid, qs, qe, 2 * index + 1 ), getMax(b, mid + 1 , se, qs, qe, 2 * index + 2 )); } // Function that initializes the // segment Tree public static void initialiseSegmentTree( int N) { seg = new int [ 4 * N]; } // Driver Code public static void main(String[] args) { int A[] = { 1 , 2 , 1 , 6 , 5 , 5 , 6 , 1 }; int B[] = { 14 , 8 , 15 , 15 , 9 , 10 , 7 , 12 }; int C = 40 ; int N = A.length; // Initialize and Build the // Segment Tree initialiseSegmentTree(N); build(B, 0 , 0 , N - 1 ); // Function Call System.out.println(maxLength(A, B, N, C)); } } |
Python3
# Python3 program for the above approach import math # Stores the segment tree node values seg = [ 0 for x in range ( 10000 )] INT_MIN = int ( - 10000000 ) # Function to find maximum element # in the given range def getMax(b, ss, se, qs, qe, index): # If the query is out of bounds if (se < qs or ss > qe): return int (INT_MIN / 2 ) # If the segment is completely # inside the query range if (ss > = qs and se < = qe): return seg[index] # Calculate the mid mid = int ( int (ss) + int ((se - ss) / 2 )) # Return maximum in left & right # of the segment tree recursively return max (getMax(b, ss, mid, qs, qe, 2 * index + 1 ), getMax(b, mid + 1 , se, qs, qe, 2 * index + 2 )) # Function to check if it is possible # to have such a subarray of length K def possible(a, b, n, c, k): sum = int ( 0 ) # Check for first window of size K for i in range ( 0 , k): sum + = a[i] # Calculate the total cost and # check if less than equal to c total_cost = int ( sum * k + getMax(b, 0 , n - 1 , 0 , k - 1 , 0 )) # If it satisfy the condition if (total_cost < = c): return 1 # Find the sum of current subarray # and calculate total cost for i in range (k, n): # Include the new element # of current subarray sum + = a[i] # Discard the element # of last subarray sum - = a[i - k] # Calculate total cost # and check <=c total_cost = int ( sum * k + getMax( b, 0 , n - 1 ,i - k + 1 , i, 0 )) # If possible, then # return true if (total_cost < = c): return 1 # If it is not possible return 0 # Function to find maximum length # of subarray such that sum of # maximum element in subarray in brr[] and # sum of subarray in arr[] * K is at most C def maxLength(a, b, n, c): # Base Case if (n = = 0 ): return 0 # Let maximum length be 0 max_length = int ( 0 ) low = 0 high = n # Perform Binary search while (low < = high): # Find mid value mid = int (low + int ((high - low) / 2 )) # Check if the current mid # satisfy the given condition if (possible(a, b, n, c, mid) ! = 0 ): # If yes, then store length max_length = mid low = mid + 1 # Otherwise else : high = mid - 1 # Return maximum length stored return max_length # Function that builds segment Tree def build(b, index, s, e): # If there is only one element if (s = = e): seg[index] = b[s] return # Find the value of mid mid = int (s + int ((e - s) / 2 )) # Build left and right parts # of segment tree recursively build(b, 2 * index + 1 , s, mid) build(b, 2 * index + 2 , mid + 1 , e) # Update the value at current # index seg[index] = max (seg[ 2 * index + 1 ], seg[ 2 * index + 2 ]) # Driver Code A = [ 1 , 2 , 1 , 6 , 5 , 5 , 6 , 1 ] B = [ 14 , 8 , 15 , 15 , 9 , 10 , 7 , 12 ] C = int ( 40 ) N = len (A) # Initialize and Build the # Segment Tree build(B, 0 , 0 , N - 1 ) # Function Call print ((maxLength(A, B, N, C))) # This code is contributed by Stream_Cipher |
C#
// C# program for the above approach using System; class GFG{ // Stores the segment tree node values static int [] seg; // Function to find maximum length // of subarray such that sum of // maximum element in subarray in brr[] and // sum of subarray in arr[] * K is at most C static int maxLength( int [] a, int [] b, int n, int c) { // Base Case if (n == 0) return 0; // Let maximum length be 0 int max_length = 0; int low = 0, high = n; // Perform Binary search while (low <= high) { // Find mid value int mid = low + (high - low) / 2; // Check if the current mid // satisfy the given condition if (possible(a, b, n, c, mid)) { // If yes, then store length max_length = mid; low = mid + 1; } // Otherwise else high = mid - 1; } // Return maximum length stored return max_length; } // Function to check if it is possible // to have such a subarray of length K static bool possible( int [] a, int [] b, int n, int c, int k) { int sum = 0; // Check for first window of size K for ( int i = 0; i < k; i++) { sum += a[i]; } // Calculate the total cost and // check if less than equal to c int total_cost = sum * k + getMax(b, 0, n - 1, 0, k - 1, 0); // If it satisfy the condition if (total_cost <= c) return true ; // Find the sum of current subarray // and calculate total cost for ( int i = k; i < n; i++) { // Include the new element // of current subarray sum += a[i]; // Discard the element // of last subarray sum -= a[i - k]; // Calculate total cost // and check <=c total_cost = sum * k + getMax(b, 0, n - 1, i - k + 1, i, 0); // If possible, then // return true if (total_cost <= c) return true ; } // If it is not possible return false ; } // Function that builds segment Tree static void build( int [] b, int index, int s, int e) { // If there is only one element if (s == e) { seg[index] = b[s]; return ; } // Find the value of mid int mid = s + (e - s) / 2; // Build left and right parts // of segment tree recursively build(b, 2 * index + 1, s, mid); build(b, 2 * index + 2, mid + 1, e); // Update the value at current // index seg[index] = Math.Max( seg[2 * index + 1], seg[2 * index + 2]); } // Function to find maximum element // in the given range public static int getMax( int [] b, int ss, int se, int qs, int qe, int index) { // If the query is out of bounds if (se < qs || ss > qe) return Int32.MinValue / 2; // If the segment is completely // inside the query range if (ss >= qs && se <= qe) return seg[index]; // Calculate the mid int mid = ss + (se - ss) / 2; // Return maximum in left & right // of the segment tree recursively return Math.Max( getMax(b, ss, mid, qs, qe, 2 * index + 1), getMax(b, mid + 1, se, qs, qe, 2 * index + 2)); } // Function that initializes the // segment Tree static void initialiseSegmentTree( int N) { seg = new int [4 * N]; } // Driver Code static void Main() { int [] A = { 1, 2, 1, 6, 5, 5, 6, 1 }; int [] B = { 14, 8, 15, 15, 9, 10, 7, 12 }; int C = 40; int N = A.Length; // Initialize and Build the // Segment Tree initialiseSegmentTree(N); build(B, 0, 0, N - 1); // Function Call Console.WriteLine(maxLength(A, B, N, C)); } } // This code is contributed by divyesh072019 |
Javascript
<script> // javascript program for the above approach // Stores the segment tree node values var seg; // Function to find maximum length // of subarray such that sum of // maximum element in subarray in brr and // sum of subarray in arr * K is at most C function maxLength(a , b , n , c) { // Base Case if (n == 0) return 0; // Let maximum length be 0 var max_length = 0; var low = 0, high = n; // Perform Binary search while (low <= high) { // Find mid value var mid = low + parseInt((high - low) / 2); // Check if the current mid // satisfy the given condition if (possible(a, b, n, c, mid)) { // If yes, then store length max_length = mid; low = mid + 1; } // Otherwise else high = mid - 1; } // Return maximum length stored return max_length; } // Function to check if it is possible // to have such a subarray of length K function possible(a , b , n , c , k) { var sum = 0; // Check for first window of size K for (i = 0; i < k; i++) { sum += a[i]; } // Calculate the total cost and // check if less than equal to c var total_cost = sum * k + getMax(b, 0, n - 1, 0, k - 1, 0); // If it satisfy the condition if (total_cost <= c) return true ; // Find the sum of current subarray // and calculate total cost for (i = k; i < n; i++) { // Include the new element // of current subarray sum += a[i]; // Discard the element // of last subarray sum -= a[i - k]; // Calculate total cost // and check <=c total_cost = sum * k + getMax(b, 0, n - 1, i - k + 1, i, 0); // If possible, then // return true if (total_cost <= c) return true ; } // If it is not possible return false ; } // Function that builds segment Tree function build(b , index , s , e) { // If there is only one element if (s == e) { seg[index] = b[s]; return ; } // Find the value of mid var mid = s + parseInt((e - s) / 2); // Build left and right parts // of segment tree recursively build(b, 2 * index + 1, s, mid); build(b, 2 * index + 2, mid + 1, e); // Update the value at current // index seg[index] = Math.max(seg[2 * index + 1], seg[2 * index + 2]); } // Function to find maximum element // in the given range function getMax(b , ss , se , qs , qe , index) { // If the query is out of bounds if (se < qs || ss > qe) return parseInt(Number.MIN_VALUE / 2); // If the segment is completely // inside the query range if (ss >= qs && se <= qe) return seg[index]; // Calculate the mid var mid = ss + (se - ss) / 2; // Return maximum in left & right // of the segment tree recursively return Math.max(getMax(b, ss, mid, qs, qe, 2 * index + 1), getMax(b, mid + 1, se, qs, qe, 2 * index + 2)); } // Function that initializes the // segment Tree function initialiseSegmentTree(N) { seg = Array(4 * N).fill(0); } // Driver Code var A = [ 1, 2, 1, 6, 5, 5, 6, 1 ]; var B = [ 14, 8, 15, 15, 9, 10, 7, 12 ]; var C = 40; var N = A.length; // Initialize and Build the // Segment Tree initialiseSegmentTree(N); build(B, 0, 0, N - 1); // Function Call document.write(maxLength(A, B, N, C)); // This code contributed by aashish1995 </script> |
3
Time Complexity: O(N*(log N)2)
Auxiliary Space: O(N)
Efficient Approach: To optimize the above approach, the idea is to use a Deque by using a monotone queue such that for each subarray of fixed length we can find a maximum in O(1) time. For any subarray in the range [i, i + K – 1] the value expression to be calculated is given by:
Below are the steps:
- Perform the Binary Search over the range [0, N] to find the maximum possible size of the subarray.
- Initialize low as 0 and high as N.
- Find the value of mid as (low + high)/2.
- Check if it is possible to get the maximum size of the subarray as mid or not as:
- Use deque to find the maximum element in each subarray of size K in the array brr[].
- Find the value of the expression and if it at most C then break out of this condition.
- Else check for all possible subarray size mid and if the value of the expression and if it at most C then break out of this condition.
- Return false if none of the above conditions satisfies.
- If the current mid satisfies the given conditions then update maximum length as mid and low as (mid + 1).
- Else Update high as (mid – 1).
- After the above steps, print the value of the maximum length stored.
Below is the implementation of the above approach:
C++
// C++ program for the above approach #include <bits/stdc++.h> using namespace std; // Function to check if it is possible // to have such a subarray of length K bool possible( int a[], int b[], int n, int c, int k) { // Finds the maximum element // in each window of size k deque < int > dq; // Check for window of size K int sum = 0; // For all possible subarrays of // length k for ( int i = 0; i < k; i++) { sum += a[i]; // Until deque is empty while (dq.size() > 0 && b[i] > b[dq.back()]) dq.pop_back(); dq.push_back(i); } // Calculate the total cost and // check if less than equal to c int total_cost = sum * k + b[dq.front()]; if (total_cost <= c) return true ; // Find sum of current subarray // and the total cost for ( int i = k; i < n; i++) { // Include the new element // of current subarray sum += a[i]; // Discard the element // of last subarray sum -= a[i - k]; // Remove all the elements // in the old window while (dq.size() > 0 && dq.front() <= i - k) dq.pop_front(); while (dq.size() > 0 && b[i] > b[dq.back()]) dq.pop_back(); dq.push_back(i); // Calculate total cost // and check <=c total_cost = sum * k + b[dq.front()]; // If current subarray // length satisfies if (total_cost <= c) return true ; } // If it is not possible return false ; } // Function to find maximum length // of subarray such that sum of // maximum element in subarray in brr[] and // sum of subarray in arr[] * K is at most C int maxLength( int a[], int b[], int n, int c) { // Base Case if (n == 0) return 0; // Let maximum length be 0 int max_length = 0; int low = 0, high = n; // Perform Binary search while (low <= high) { // Find mid value int mid = low + (high - low) / 2; // Check if the current mid // satisfy the given condition if (possible(a, b, n, c, mid)) { // If yes, then store length max_length = mid; low = mid + 1; } // Otherwise else high = mid - 1; } // Return maximum length stored return max_length; } // Driver Code int main() { int A[] = { 1, 2, 1, 6, 5, 5, 6, 1 }; int B[] = { 14, 8, 15, 15, 9, 10, 7, 12 }; int N = sizeof (A)/ sizeof (A[0]); int C = 40; cout << maxLength(A, B, N, C); return 0; } // This code is contributed by Dharanendra L V |
Java
// Java program for the above approach import java.io.*; import java.util.*; class GFG { // Function to find maximum length // of subarray such that sum of // maximum element in subarray in brr[] and // sum of subarray in arr[] * K is at most C public static int maxLength( int a[], int b[], int n, int c) { // Base Case if (n == 0 ) return 0 ; // Let maximum length be 0 int max_length = 0 ; int low = 0 , high = n; // Perform Binary search while (low <= high) { // Find mid value int mid = low + (high - low) / 2 ; // Check if the current mid // satisfy the given condition if (possible(a, b, n, c, mid)) { // If yes, then store length max_length = mid; low = mid + 1 ; } // Otherwise else high = mid - 1 ; } // Return maximum length stored return max_length; } // Function to check if it is possible // to have such a subarray of length K public static boolean possible( int a[], int b[], int n, int c, int k) { // Finds the maximum element // in each window of size k Deque<Integer> dq = new LinkedList<Integer>(); // Check for window of size K int sum = 0 ; // For all possible subarrays of // length k for ( int i = 0 ; i < k; i++) { sum += a[i]; // Until deque is empty while (dq.size() > 0 && b[i] > b[dq.peekLast()]) dq.pollLast(); dq.addLast(i); } // Calculate the total cost and // check if less than equal to c int total_cost = sum * k + b[dq.peekFirst()]; if (total_cost <= c) return true ; // Find sum of current subarray // and the total cost for ( int i = k; i < n; i++) { // Include the new element // of current subarray sum += a[i]; // Discard the element // of last subarray sum -= a[i - k]; // Remove all the elements // in the old window while (dq.size() > 0 && dq.peekFirst() <= i - k) dq.pollFirst(); while (dq.size() > 0 && b[i] > b[dq.peekLast()]) dq.pollLast(); dq.add(i); // Calculate total cost // and check <=c total_cost = sum * k + b[dq.peekFirst()]; // If current subarray // length satisfies if (total_cost <= c) return true ; } // If it is not possible return false ; } // Driver Code public static void main(String[] args) { int A[] = { 1 , 2 , 1 , 6 , 5 , 5 , 6 , 1 }; int B[] = { 14 , 8 , 15 , 15 , 9 , 10 , 7 , 12 }; int N = A.length; int C = 40 ; System.out.println( maxLength(A, B, N, C)); } } |
Python3
# Python3 program for the above approach # Function to find maximum length # of subarray such that sum of # maximum element in subarray in brr[] and # sum of subarray in []arr * K is at most C def maxLength(a, b, n, c): # Base Case if (n = = 0 ): return 0 # Let maximum length be 0 max_length = 0 low = 0 high = n # Perform Binary search while (low < = high): # Find mid value mid = int (low + (high - low) / 2 ) # Check if the current mid # satisfy the given condition if (possible(a, b, n, c, mid)): # If yes, then store length max_length = mid low = mid + 1 # Otherwise else : high = mid - 1 # Return maximum length stored return max_length # Function to check if it is possible # to have such a subarray of length K def possible(a, b, n, c, k): # Finds the maximum element # in each window of size k dq = [] # Check for window of size K Sum = 0 # For all possible subarrays of # length k for i in range (k): Sum + = a[i] # Until deque is empty while ( len (dq) > 0 and b[i] > b[dq[ len (dq) - 1 ]]): dq.pop( len (dq) - 1 ) dq.append(i) # Calculate the total cost and # check if less than equal to c total_cost = Sum * k + b[dq[ 0 ]] if (total_cost < = c): return True # Find sum of current subarray # and the total cost for i in range (k, n): # Include the new element # of current subarray Sum + = a[i] # Discard the element # of last subarray Sum - = a[i - k] # Remove all the elements # in the old window while ( len (dq) > 0 and dq[ 0 ] < = i - k): dq.pop( 0 ) while ( len (dq) > 0 and b[i] > b[dq[ len (dq) - 1 ]]): dq.pop( len (dq) - 1 ) dq.append(i) # Calculate total cost # and check <=c total_cost = Sum * k + b[dq[ 0 ]] # If current subarray # length satisfies if (total_cost < = c): return True # If it is not possible return False # Driver Code A = [ 1 , 2 , 1 , 6 , 5 , 5 , 6 , 1 ] B = [ 14 , 8 , 15 , 15 , 9 , 10 , 7 , 12 ] N = len (A) C = 40 print (maxLength(A, B, N, C)) # This code is contributed by avanitrachhadiya2155 |
C#
// C# program for the above approach using System; using System.Collections.Generic; public class GFG { // Function to find maximum length // of subarray such that sum of // maximum element in subarray in brr[] and // sum of subarray in []arr * K is at most C public static int maxLength( int []a, int []b, int n, int c) { // Base Case if (n == 0) return 0; // Let maximum length be 0 int max_length = 0; int low = 0, high = n; // Perform Binary search while (low <= high) { // Find mid value int mid = low + (high - low) / 2; // Check if the current mid // satisfy the given condition if (possible(a, b, n, c, mid)) { // If yes, then store length max_length = mid; low = mid + 1; } // Otherwise else high = mid - 1; } // Return maximum length stored return max_length; } // Function to check if it is possible // to have such a subarray of length K public static bool possible( int []a, int []b, int n, int c, int k) { // Finds the maximum element // in each window of size k List< int > dq = new List< int >(); // Check for window of size K int sum = 0; // For all possible subarrays of // length k for ( int i = 0; i < k; i++) { sum += a[i]; // Until deque is empty while (dq.Count > 0 && b[i] > b[dq[dq.Count - 1]]) dq.RemoveAt(dq.Count - 1); dq.Add(i); } // Calculate the total cost and // check if less than equal to c int total_cost = sum * k + b[dq[0]]; if (total_cost <= c) return true ; // Find sum of current subarray // and the total cost for ( int i = k; i < n; i++) { // Include the new element // of current subarray sum += a[i]; // Discard the element // of last subarray sum -= a[i - k]; // Remove all the elements // in the old window while (dq.Count > 0 && dq[0] <= i - k) dq.RemoveAt(0); while (dq.Count > 0 && b[i] > b[dq[dq.Count - 1]]) dq.RemoveAt(dq.Count - 1); dq.Add(i); // Calculate total cost // and check <=c total_cost = sum * k + b[dq[0]]; // If current subarray // length satisfies if (total_cost <= c) return true ; } // If it is not possible return false ; } // Driver Code public static void Main(String[] args) { int []A = { 1, 2, 1, 6, 5, 5, 6, 1 }; int []B = { 14, 8, 15, 15, 9, 10, 7, 12 }; int N = A.Length; int C = 40; Console.WriteLine( maxLength(A, B, N, C)); } } // This code is contributed by Amit Katiyar |
Javascript
<script> // Javascript program for the above approach // Function to check if it is possible // to have such a subarray of length K function possible(a, b, n, c, k) { // Finds the maximum element // in each window of size k let dq = []; // Check for window of size K let sum = 0; // For all possible subarrays of // length k for (let i = 0; i < k; i++) { sum += a[i]; // Until deque is empty while (dq.length > 0 && b[i] > b[dq[dq.length - 1]]) dq.pop(); dq.push(i); } // Calculate the total cost and // check if less than equal to c let total_cost = sum * k + b[dq[0]]; if (total_cost <= c) return true ; // Find sum of current subarray // and the total cost for (let i = k; i < n; i++) { // Include the new element // of current subarray sum += a[i]; // Discard the element // of last subarray sum -= a[i - k]; // Remove all the elements // in the old window while (dq.length > 0 && dq[0] <= i - k) dq.pop(); while (dq.length > 0 && b[i] > b[dq[dq.length - 1]]) dq.pop(); dq.push(i); // Calculate total cost // and check <=c total_cost = sum * k + b[dq[0]]; // If current subarray // length satisfies if (total_cost <= c) return true ; } // If it is not possible return false ; } // Function to find maximum length // of subarray such that sum of // maximum element in subarray in brr[] and // sum of subarray in arr[] * K is at most C function maxLength(a, b, n, c) { // Base Case if (n == 0) return 0; // Let maximum length be 0 let max_length = 0; let low = 0, high = n; // Perform Binary search while (low <= high) { // Find mid value let mid = low + parseInt((high - low) / 2, 10); // Check if the current mid // satisfy the given condition if (possible(a, b, n, c, mid)) { // If yes, then store length max_length = mid; low = mid + 1; } // Otherwise else high = mid - 1; } // Return maximum length stored return max_length; } let A = [ 1, 2, 1, 6, 5, 5, 6, 1 ]; let B = [ 14, 8, 15, 15, 9, 10, 7, 12 ]; let N = A.length; let C = 40; document.write(maxLength(A, B, N, C)); </script> |
3
Time Complexity: O(N*log N)
Auxiliary Space: O(N)
Related Topic: Subarrays, Subsequences, and Subsets in Array
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