Given two arrays W[] and C[] containing weight and cost of N (1 to N) items respectively, and an integer K, find a segment from 1 to N, such that the total weight of the segment is at most K and the total cost is maximum. Print the cost of this segment.
Examples:
Input: N = 6, K = 20, W[] = {9, 7, 6, 5, 8, 4}, C[] = {7, 1, 3, 6, 8, 3}
Output: 17
Explanation: Pick the segment having index (2, 3, 4) Weight of segment {6, 5, 8} is 19. Cost of segment = 3 + 6 + 8 = 17 which is maximum possible.Input: N = 3, K = 55, W[] = {10, 20, 30}, C[] = {60, 100, 120}
Output: 220
Naive Approach: The approach is to find all the segments whose weight is at most k and keep track of the maximum cost. For each element find a segment starting from this element.
Below is the implementation of the above approach.
C++
// C++ code to find maximum cost of // a segment whose weight is at most K. #include <bits/stdc++.h> using namespace std; // Function to find the maximum cost of // a segment whose weight is at most k. int findMaxCost( int W[], int C[], int N, int K) { // Variable to keep track of // current weight. int weight = 0; // Variable to keep track // of current cost. int cost = 0; // variable to keep track of // maximum cost of a segment // whose weight is at most K. int maxCost = 0; // Loop to get segment // having weight at most K for ( int l = 0; l < N; l++) { weight = 0; cost = 0; for ( int r = l; r < N; r++) { weight += W[r]; cost += C[r]; if (weight <= K) maxCost = max(maxCost, cost); } } return maxCost; } // Driver code int main() { int W[] = { 9, 7, 6, 5, 8, 4 }; int C[] = { 7, 1, 3, 6, 8, 3 }; int N = sizeof (W) / sizeof (W[0]); int K = 20; cout << findMaxCost(W, C, N, K); return 0; } |
Java
// Java code to find maximum cost of // a segment whose weight is at most K. class GFG{ // Function to find the maximum cost of // a segment whose weight is at most k. static int findMaxCost( int W[], int C[], int N, int K) { // Variable to keep track of // current weight. int weight = 0 ; // Variable to keep track // of current cost. int cost = 0 ; // variable to keep track of // maximum cost of a segment // whose weight is at most K. int maxCost = 0 ; // Loop to get segment // having weight at most K for ( int l = 0 ; l < N; l++) { weight = 0 ; cost = 0 ; for ( int r = l; r < N; r++) { weight += W[r]; cost += C[r]; if (weight <= K) maxCost = Math.max(maxCost, cost); } } return maxCost; } // Driver code public static void main(String[] args) { int W[] = { 9 , 7 , 6 , 5 , 8 , 4 }; int C[] = { 7 , 1 , 3 , 6 , 8 , 3 }; int N = W.length; int K = 20 ; System.out.print(findMaxCost(W, C, N, K)); } } // This code is contributed by 29AjayKumar |
Python3
# Python code to find maximum cost of # a segment whose weight is at most K. # Function to find the maximum cost of # a segment whose weight is at most k. def findMaxCost(W, C, N, K) : # Variable to keep track of # current weight. weight = 0 ; # Variable to keep track # of current cost. cost = 0 ; # variable to keep track of # maximum cost of a segment # whose weight is at most K. maxCost = 0 ; # Loop to get segment # having weight at most K for l in range (N): weight = 0 ; cost = 0 ; for r in range (l, N): weight + = W[r]; cost + = C[r]; if (weight < = K): maxCost = max (maxCost, cost); return maxCost; # Driver code W = [ 9 , 7 , 6 , 5 , 8 , 4 ]; C = [ 7 , 1 , 3 , 6 , 8 , 3 ]; N = len (W); K = 20 ; print (findMaxCost(W, C, N, K)); # This code is contributed by Saurabh Jaiswal |
C#
// C# code to find maximum cost of // a segment whose weight is at most K. using System; class GFG { // Function to find the maximum cost of // a segment whose weight is at most k. static int findMaxCost( int [] W, int [] C, int N, int K) { // Variable to keep track of // current weight. int weight = 0; // Variable to keep track // of current cost. int cost = 0; // variable to keep track of // maximum cost of a segment // whose weight is at most K. int maxCost = 0; // Loop to get segment // having weight at most K for ( int l = 0; l < N; l++) { weight = 0; cost = 0; for ( int r = l; r < N; r++) { weight += W[r]; cost += C[r]; if (weight <= K) maxCost = Math.Max(maxCost, cost); } } return maxCost; } // Driver code public static void Main() { int [] W = { 9, 7, 6, 5, 8, 4 }; int [] C = { 7, 1, 3, 6, 8, 3 }; int N = W.Length; int K = 20; Console.WriteLine(findMaxCost(W, C, N, K)); } } // This code is contributed by ukasp. |
Javascript
<script> // JavaScript code to find maximum cost of // a segment whose weight is at most K. // Function to find the maximum cost of // a segment whose weight is at most k. function findMaxCost(W, C, N, K) { // Variable to keep track of // current weight. let weight = 0; // Variable to keep track // of current cost. let cost = 0; // variable to keep track of // maximum cost of a segment // whose weight is at most K. let maxCost = 0; // Loop to get segment // having weight at most K for (let l = 0; l < N; l++) { weight = 0; cost = 0; for (let r = l; r < N; r++) { weight += W[r]; cost += C[r]; if (weight <= K) maxCost = Math.max(maxCost, cost); } } return maxCost; } // Driver code let W = [ 9, 7, 6, 5, 8, 4 ]; let C = [ 7, 1, 3, 6, 8, 3 ]; let N = W.length; let K = 20; document.write(findMaxCost(W, C, N, K)); // This code is contributed by Potta Lokesh </script> |
17
Time Complexity: O(N*N), as we are using nested loops to traverse N*N times.
Auxiliary Space: O(1), as we are not using any extra space.
Efficient Approach: An efficient approach is to use the sliding window technique.
- Let l and r denote the index of the first and last element in the current window respectively.
- Start traversing the array and keep track of total weight and total cost of elements in the current window and the maximum total cost found till now.
- While weight of window is greater than k, keep removing elements from the start of window.
- Now update the maximum cost.
- After traversing all the items return the maximum cost.
Below is the implementation of the above approach.
C++
// C++ code to find maximum cost of // a segment whose weight is at most K. #include <bits/stdc++.h> using namespace std; // Function to find the maximum cost of // a segment whose weight is at most K. int findMaxCost( int W[], int C[], int N, int K) { // Variable to keep track // of current weight. int weight = 0; // Variable to keep track // of current cost. int cost = 0; // Variable to keep track of // maximum cost of a segment // whose weight is at most K. int maxCost = 0; // Loop to implement // sliding window technique int l = 0; for ( int r = 0; r < N; r++) { // Add current element to the window. weight += W[r]; cost += C[r]; // Keep removing elements // from the start of current window // while weight is greater than K while (weight > K) { weight -= W[l]; cost -= C[l]; l++; } // Update maxCost maxCost = max(maxCost, cost); } return maxCost; } // Driver code int main() { int W[] = {9, 7, 6, 5, 8, 4}; int C[] = {7, 1, 3, 6, 8, 3}; int N = sizeof (W) / sizeof (W[0]); int K = 20; cout << findMaxCost(W, C, N, K); return 0; } |
Java
// Java code to find maximum cost of // a segment whose weight is at most K. class GFG{ // Function to find the maximum cost of // a segment whose weight is at most K. static int findMaxCost( int W[], int C[], int N, int K) { // Variable to keep track // of current weight. int weight = 0 ; // Variable to keep track // of current cost. int cost = 0 ; // Variable to keep track of // maximum cost of a segment // whose weight is at most K. int maxCost = 0 ; // Loop to implement // sliding window technique int l = 0 ; for ( int r = 0 ; r < N; r++) { // Add current element to the window. weight += W[r]; cost += C[r]; // Keep removing elements // from the start of current window // while weight is greater than K while (weight > K) { weight -= W[l]; cost -= C[l]; l++; } // Update maxCost maxCost = Math.max(maxCost, cost); } return maxCost; } // Driver code public static void main(String[] args) { int W[] = { 9 , 7 , 6 , 5 , 8 , 4 }; int C[] = { 7 , 1 , 3 , 6 , 8 , 3 }; int N = W.length; int K = 20 ; System.out.print(findMaxCost(W, C, N, K)); } } // This code is contributed by 29AjayKumar |
Python3
# Python 3 code to find maximum cost of # a segment whose weight is at most K. # Function to find the maximum cost of # a segment whose weight is at most K. def findMaxCost(W, C, N, K): # Variable to keep track # of current weight. weight = 0 # Variable to keep track # of current cost. cost = 0 # Variable to keep track of # maximum cost of a segment # whose weight is at most K. maxCost = 0 # Loop to implement # sliding window technique l = 0 for r in range (N): # Add current element to the window. weight + = W[r] cost + = C[r] # Keep removing elements # from the start of current window # while weight is greater than K while (weight > K): weight - = W[l] cost - = C[l] l + = 1 # Update maxCost maxCost = max (maxCost, cost) return maxCost # Driver code if __name__ = = "__main__" : W = [ 9 , 7 , 6 , 5 , 8 , 4 ] C = [ 7 , 1 , 3 , 6 , 8 , 3 ] N = len (W) K = 20 print (findMaxCost(W, C, N, K)) # This code is contributed by gaurav01. |
C#
// C# code to find maximum cost of // a segment whose weight is at most K. using System; using System.Collections.Generic; public class GFG{ // Function to find the maximum cost of // a segment whose weight is at most K. static int findMaxCost( int []W, int []C, int N, int K) { // Variable to keep track // of current weight. int weight = 0; // Variable to keep track // of current cost. int cost = 0; // Variable to keep track of // maximum cost of a segment // whose weight is at most K. int maxCost = 0; // Loop to implement // sliding window technique int l = 0; for ( int r = 0; r < N; r++) { // Add current element to the window. weight += W[r]; cost += C[r]; // Keep removing elements // from the start of current window // while weight is greater than K while (weight > K) { weight -= W[l]; cost -= C[l]; l++; } // Update maxCost maxCost = Math.Max(maxCost, cost); } return maxCost; } // Driver code public static void Main(String[] args) { int []W = {9, 7, 6, 5, 8, 4}; int []C = {7, 1, 3, 6, 8, 3}; int N = W.Length; int K = 20; Console.Write(findMaxCost(W, C, N, K)); } } // This code is contributed by shikhasingrajput |
Javascript
<script> // JavaScript code to find maximum cost of // a segment whose weight is at most K. // Function to find the maximum cost of // a segment whose weight is at most K. const findMaxCost = (W, C, N, K) => { // Variable to keep track // of current weight. let weight = 0; // Variable to keep track // of current cost. let cost = 0; // Variable to keep track of // maximum cost of a segment // whose weight is at most K. let maxCost = 0; // Loop to implement // sliding window technique let l = 0; for (let r = 0; r < N; r++) { // Add current element to the window. weight += W[r]; cost += C[r]; // Keep removing elements // from the start of current window // while weight is greater than K while (weight > K) { weight -= W[l]; cost -= C[l]; l++; } // Update maxCost maxCost = Math.max(maxCost, cost); } return maxCost; } // Driver code let W = [9, 7, 6, 5, 8, 4]; let C = [7, 1, 3, 6, 8, 3]; let N = W.length; let K = 20; document.write(findMaxCost(W, C, N, K)); // This code is contributed by rakesh sahani. </script> |
17
Time Complexity: O(N), as we are using a loop to traverse N times.
Auxiliary Space: O(1), as we are not using any extra space.
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