Perfect Squares
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[1] = 1;
for (int i = 2; i <= n; i++) {
dp[i] = i;
for (int j = 1; j * j <= i; j++) {
dp[i] = Math.min(dp[i], dp[i - j * j] + 1);
}
}
return dp[n];
}
}
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