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53 | 53 |
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54 | 54 | <!-- 这里可写通用的实现逻辑 -->
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55 | 55 |
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| 56 | +两次 dp,`dp1[i][j]` 表示 i ~ j 的子串是否是回文,可以参考 [5. 最长回文子串](../../solution/0000-0099/0005.Longest%20Palindromic%20Substring/README.md)。`dp2[i]` 表示以 i 结尾的子串最少需要分割几次,如果本来就是回文串(`dp[0][i] == true`)就不需要分割,否则枚举分割点 `j` |
| 57 | + |
56 | 58 | <!-- tabs:start -->
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57 | 59 |
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58 | 60 | ### **Python3**
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59 | 61 |
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60 | 62 | <!-- 这里可写当前语言的特殊实现逻辑 -->
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61 | 63 |
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62 | 64 | ```python
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63 |
| - |
| 65 | +class Solution: |
| 66 | + def minCut(self, s: str) -> int: |
| 67 | + n = len(s) |
| 68 | + dp1 = [[False] * n for _ in range(n)] |
| 69 | + for i in range(n - 1, -1, -1): |
| 70 | + for j in range(i, n): |
| 71 | + dp1[i][j] = s[i] == s[j] and (j - i < 3 or dp1[i + 1][j - 1]) |
| 72 | + dp2 = [0] * n |
| 73 | + for i in range(n): |
| 74 | + if not dp1[0][i]: |
| 75 | + dp2[i] = i |
| 76 | + for j in range(1, i + 1): |
| 77 | + if dp1[j][i]: |
| 78 | + dp2[i] = min(dp2[i], dp2[j - 1] + 1) |
| 79 | + return dp2[-1] |
64 | 80 | ```
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65 | 81 |
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66 | 82 | ### **Java**
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67 | 83 |
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68 | 84 | <!-- 这里可写当前语言的特殊实现逻辑 -->
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69 | 85 |
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70 | 86 | ```java
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| 87 | +class Solution { |
| 88 | + public int minCut(String s) { |
| 89 | + int n = s.length(); |
| 90 | + boolean[][] dp1 = new boolean[n][n]; |
| 91 | + for (int i = n - 1; i >= 0; i--) { |
| 92 | + for (int j = i; j < n; j++) { |
| 93 | + dp1[i][j] = s.charAt(i) == s.charAt(j) && (j - i < 3 || dp1[i + 1][j - 1]); |
| 94 | + } |
| 95 | + } |
| 96 | + int[] dp2 = new int[n]; |
| 97 | + for (int i = 0; i < n; i++) { |
| 98 | + if (!dp1[0][i]) { |
| 99 | + dp2[i] = i; |
| 100 | + for (int j = 1; j <= i; j++) { |
| 101 | + if (dp1[j][i]) { |
| 102 | + dp2[i] = Math.min(dp2[i], dp2[j - 1] + 1); |
| 103 | + } |
| 104 | + } |
| 105 | + } |
| 106 | + } |
| 107 | + return dp2[n - 1]; |
| 108 | + } |
| 109 | +} |
| 110 | +``` |
| 111 | + |
| 112 | +### **Go** |
| 113 | + |
| 114 | +```go |
| 115 | +func minCut(s string) int { |
| 116 | + n := len(s) |
| 117 | + dp1 := make([][]bool, n) |
| 118 | + for i := 0; i < n; i++ { |
| 119 | + dp1[i] = make([]bool, n) |
| 120 | + } |
| 121 | + for i := n - 1; i >= 0; i-- { |
| 122 | + for j := i; j < n; j++ { |
| 123 | + dp1[i][j] = s[i] == s[j] && (j-i < 3 || dp1[i+1][j-1]) |
| 124 | + } |
| 125 | + } |
| 126 | + dp2 := make([]int, n) |
| 127 | + for i := 0; i < n; i++ { |
| 128 | + if !dp1[0][i] { |
| 129 | + dp2[i] = i |
| 130 | + for j := 1; j <= i; j++ { |
| 131 | + if dp1[j][i] { |
| 132 | + dp2[i] = min(dp2[i], dp2[j-1]+1) |
| 133 | + } |
| 134 | + } |
| 135 | + } |
| 136 | + } |
| 137 | + return dp2[n-1] |
| 138 | +} |
| 139 | + |
| 140 | +func min(x, y int) int { |
| 141 | + if x < y { |
| 142 | + return x |
| 143 | + } |
| 144 | + return y |
| 145 | +} |
| 146 | +``` |
71 | 147 |
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| 148 | +### **C++** |
| 149 | + |
| 150 | +```cpp |
| 151 | +class Solution { |
| 152 | +public: |
| 153 | + int minCut(string s) { |
| 154 | + int n = s.size(); |
| 155 | + vector<vector<bool>> dp1(n, vector<bool>(n)); |
| 156 | + for (int i = n - 1; i >= 0; --i) { |
| 157 | + for (int j = i; j < n; ++j) { |
| 158 | + dp1[i][j] = s[i] == s[j] && (j - i < 3 || dp1[i + 1][j - 1]); |
| 159 | + } |
| 160 | + } |
| 161 | + vector<int> dp2(n); |
| 162 | + for (int i = 0; i < n; ++i) { |
| 163 | + if (!dp1[0][i]) { |
| 164 | + dp2[i] = i; |
| 165 | + for (int j = 1; j <= i; ++j) { |
| 166 | + if (dp1[j][i]) { |
| 167 | + dp2[i] = min(dp2[i], dp2[j - 1] + 1); |
| 168 | + } |
| 169 | + } |
| 170 | + } |
| 171 | + } |
| 172 | + return dp2[n - 1]; |
| 173 | + } |
| 174 | +}; |
72 | 175 | ```
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73 | 176 |
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74 | 177 | ### **...**
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