Given a positive integer n, find the least number of perfect square numbers (for example, 1, 4, 9, 16, …) which sum to n.
Example 1:
Input: n = 12
Output: 3
Explanation: 12 = 4 + 4 + 4.
Example 2:
Input: n = 13
Output: 2
Explanation: 13 = 4 + 9.
class Solution {
public int numSquares(int n) {
int[] dp = new int[n+1];
dp[0] = 0;
for(int i = 1; i <= n; i++){
int j = 1;
int min = Integer.MAX_VALUE;
while(i - j*j >= 0){
min = Math.min(dp[i - j*j] + 1, min);
j++;
}
dp[i] = min;
}
return dp[n];
}
}