Update 0279.完全平方数.md

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jianghongcheng
2023-06-04 23:58:00 -05:00
committed by GitHub
parent 0964e16991
commit 87e7b9def8

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@ -217,36 +217,45 @@ class Solution {
Python
先遍历物品, 再遍历背包
```python
class Solution:
def numSquares(self, n: int) -> int:
'''版本一,先遍历背包, 再遍历物品'''
# 初始化
nums = [i**2 for i in range(1, n + 1) if i**2 <= n]
dp = [10**4]*(n + 1)
dp = [float('inf')] * (n + 1)
dp[0] = 0
# 遍历背包
for j in range(1, n + 1):
# 遍历物品
for num in nums:
if j >= num:
dp[j] = min(dp[j], dp[j - num] + 1)
return dp[n]
def numSquares1(self, n: int) -> int:
'''版本二, 先遍历物品, 再遍历背包'''
# 初始化
nums = [i**2 for i in range(1, n + 1) if i**2 <= n]
dp = [10**4]*(n + 1)
dp[0] = 0
# 遍历物品
for num in nums:
# 遍历背包
for j in range(num, n + 1):
dp[j] = min(dp[j], dp[j - num] + 1)
return dp[n]
```
for i in range(1, n + 1): # 遍历背包
for j in range(1, int(i ** 0.5) + 1): # 遍历物品
# 更新凑成数字 i 所需的最少完全平方数数量
dp[i] = min(dp[i], dp[i - j * j] + 1)
return dp[n]
```
其他版本
```python
class Solution:
def numSquares(self, n: int) -> int:
# 创建动态规划数组,初始值为最大值
dp = [float('inf')] * (n + 1)
# 初始化已知情况
dp[0] = 0
# 遍历背包容量
for i in range(1, n + 1):
# 遍历完全平方数作为物品
j = 1
while j * j <= i:
# 更新最少完全平方数的数量
dp[i] = min(dp[i], dp[i - j * j] + 1)
j += 1
# 返回结果
return dp[n]
```
Go
```go
// 版本一,先遍历物品, 再遍历背包