Leetcode 279. Perfect Squares 动态规划

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.

---

不要想复杂

class Solution:
    def numSquares(self, n: int) -> int:
        dp = [i for i in range(n+1)]
        for i in range(1, n+1):
            j = 1
            while (j*j <= i):
                dp[i] = min(dp[i], dp[i-j*j]+1)
                j+=1
        return dp[n]

s = Solution()
print(s.numSquares(13))
print(s.numSquares(12))