/**
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
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*/
//leetcode submit region begin(Prohibit modification and deletion)
class Solution {
public int numSquares(int n) {
int[] dp = new int[n + 1];
dp[1] = 1;
List<Integer> squareList = new ArrayList<>();
int i = 1;
while (i * i < 10000) {
squareList.add(i * i);
i++;
}
for (i = 2; i <= n; i++) {
int min = 10000;
for (int j = 0; j < squareList.size(); j++) {
if (i - squareList.get(j) < 0) {
break;
}
if (dp[i - squareList.get(j)] + 1 < min) {
min = dp[i - squareList.get(j)] + 1;
}
}
dp[i] = min;
}
return dp[n];
}
}
//leetcode submit region end(Prohibit modification and deletion)
