leetcode 279: Perfect Squares
953 ワード
Perfect Squares
Total Accepted: 605
Total Submissions: 1956
Given a positive integer n, find the least number of perfect square numbers (for example,
For example, given n =
離散リュックの問題はDPで解決する.
[CODE]
Total Accepted: 605
Total Submissions: 1956
Given a positive integer n, find the least number of perfect square numbers (for example,
1, 4, 9, 16, ...
) which sum to n. For example, given n =
12
, return 3
because 12 = 4 + 4 + 4
; given n = 13
, return 2
because 13 = 4 + 9
. [考え方]離散リュックの問題はDPで解決する.
[CODE]
public class Solution {
public int numSquares(int n) {
int[] d = new int[n+1];
d[1] = 1;
for(int i=2; i<=n; i++) {
int min = Integer.MAX_VALUE;
int j=1;
while(j*j<=i) {
if(j*j==i) {
min = 1; break;
}
min = Math.min(min, d[i-j*j]+1);
++j;
}
d[i] = min;
}
return d[n];
}
}