279. Perfect Squares

 279. Perfect Squares

Given an integer n, return the least number of perfect square numbers that sum to n.

A perfect square is an integer that is the square of an integer; in other words, it is the product of some integer with itself. For example, 1, 4, 9, and 16 are perfect squares while 3 and 11 are not.

 

Example 1:

Input: n = 12
Output: 3
Explanation: 12 = 4 + 4 + 4.

Example 2:

Input: n = 13
Output: 2
Explanation: 13 = 4 + 9.

 

Constraints:

• 1 <= n <= 104



• Solution To the Above Question

class Solution {

public:

    int numSquares(int n) {

        vector<int> dp(n+1,INT_MAX);

        dp[0]=0;

        int i=1;

        while(i*i<=n){

            int square=i*i;

            for(int j=square; j<=n; j++){

                dp[j]=min(dp[j],dp[j-square]+1);

            }

            i++;

        }

        

        return dp[n];

        

    }

};