Given 3 integers a, b and c indicating number of candies present in three bags. You need to find whether we can empty all the bags by performing a specific operation where in each operation, you can eat 2 candies from one bag and 1 candy each from the other 2 bags. It is not permittable to skip any bag i.e either 1 or 2 candies must be eaten from each bag in each operation. Return true if possible else return false.
Examples:
Input: 4, 2, 2
Output: true
Explanation:
Operation 1: you can eat 2 candies from bag1 and 1 from bag2 and bag3 each.
Candies left after operation 1
bag1 = 2, bag2 = 1, bag3 = 1
Operation 2: you can eat 2 candies from bag1 and 1 from each bag2 and bag3 each
Candies left after operation 2
bag1 = 0, bag2 = 0, bag3 = 0
Hence it is possible to empty all the bagsInput: 3, 4, 2
Output: false
Naive Approach: Iterate through the variables until all three does not become 0. At every iteration reduce the maximum element by 2 and remaining variables by 1.
Time Complexity: O(N), where N is value of maximum variable of a, b and c
Efficient Approach: The given problem can be solved with the efficient approach by making the following observations:
- In each operation we’ll pick 1+2+1=4 candies, hence the sum of all the candies in bag1, bag2, and bag3 must be divisible by 4.
- Number of operations required to empty all the bags would be (sum of all candies)/4.
- We have to pick either 1 or 2 candies from a bag at any operation, hence the minimum candies present of the 3 bags must be greater than or equal to the number of operations.
C++
// C++ code for the above approach #include <bits/stdc++.h> #define ll long long using namespace std; bool can_empty(ll a, ll b, ll c) { // If total candies are not multiple // of 4 then its not possible to be // left with 0 candies if ((a + b + c) % 4 != 0) return false ; else { // If minimum candies of three bags // are less than number of operations // required then the task is not possible int m = min(a, min(b, c)); if (m < ((a + b + c) / 4)) return false ; } return true ; } // Driver code int main() { ll a = 4, b = 2, c = 2; cout << (can_empty(a, b, c) ? "true" : "false" ) << endl; a = 3, b = 4, c = 2; cout << (can_empty(a, b, c) ? "true" : "false" ) << endl; return 0; } |
Java
// Java code for the above approach import java.util.*; class GFG{ static boolean can_empty( int a, int b, int c) { // If total candies are not multiple // of 4 then its not possible to be // left with 0 candies if ((a + b + c) % 4 != 0 ) return false ; else { // If minimum candies of three bags // are less than number of operations // required then the task is not possible int m = Math.min(a, Math.min(b, c)); if (m < ((a + b + c) / 4 )) return false ; } return true ; } // Driver Code public static void main(String[] args) { int a = 4 , b = 2 , c = 2 ; System.out.println(can_empty(a, b, c) ? "true" : "false" ); a = 3 ; b = 4 ; c = 2 ; System.out.println(can_empty(a, b, c) ? "true" : "false" ); } } // This code is contributed by code_hunt |
Python3
# Python code for the above approach def can_empty(a, b, c): # If total candies are not multiple # of 4 then its not possible to be # left with 0 candies if ((a + b + c) % 4 ! = 0 ) : return False ; else : # If minimum candies of three bags # are less than number of operations # required then the task is not possible m = min (a, min (b, c)); if (m < (a + b + c) / / 4 ) : return False ; return True ; # Driver code a = 4 b = 2 c = 2 print ( "true" if can_empty(a, b, c) else "false" ); a = 3 b = 4 c = 2 print ( "true" if can_empty(a, b, c) else "false" ); # This code is contributed by _saurabh_jaiswal |
C#
using System; public class GFG { static bool can_empty( int a, int b, int c) { // If total candies are not multiple // of 4 then its not possible to be // left with 0 candies if ((a + b + c) % 4 != 0) return false ; else { // If minimum candies of three bags // are less than number of operations // required then the task is not possible int m = Math.Min(a, Math.Min(b, c)); if (m < ((a + b + c) / 4)) return false ; } return true ; } // Driver Code static public void Main() { int a = 4, b = 2, c = 2; Console.WriteLine(can_empty(a, b, c) ? "true" : "false" ); a = 3; b = 4; c = 2; Console.WriteLine(can_empty(a, b, c) ? "true" : "false" ); } } // This code is contributed by maddler. |
Javascript
<script> // Javascript code for the above approach function can_empty(a, b, c) { // If total candies are not multiple // of 4 then its not possible to be // left with 0 candies if ((a + b + c) % 4 != 0) return false ; else { // If minimum candies of three bags // are less than number of operations // required then the task is not possible let m = Math.min(a, Math.min(b, c)); if (m < Math.floor((a + b + c) / 4)) return false ; } return true ; } // Driver code let a = 4, b = 2, c = 2; document.write(can_empty(a, b, c) ? "true" : "false" ); document.write( "<br>" ); (a = 3), (b = 4), (c = 2); document.write(can_empty(a, b, c) ? "true" : "false" ); // This code is contributed by _saurabh_jaiswal </script> |
true false
Time Complexity: O(1) since no loop is used the algorithm takes up constant time to perform the operations
Space Complexity: O(1) since no extra array is used so the space taken by the algorithm is constant
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