|
44 | 44 |
|
45 | 45 | <!-- 这里可写通用的实现逻辑 -->
|
46 | 46 |
|
| 47 | +**方法一:动态规划** |
| 48 | + |
| 49 | +类似[1143. 最长公共子序列](/solution/1100-1199/1143.Longest%20Common%20Subsequence/README.md)。 |
| 50 | + |
| 51 | +定义 `dp[i][j]` 表示使得 `s1[0:i-1]` 和 `s2[0:j-1]` 两个字符串相等所需删除的字符的 ASCII 值的最小值。 |
| 52 | + |
| 53 | +时间复杂度 O(mn)。 |
| 54 | + |
47 | 55 | <!-- tabs:start -->
|
48 | 56 |
|
49 | 57 | ### **Python3**
|
50 | 58 |
|
51 | 59 | <!-- 这里可写当前语言的特殊实现逻辑 -->
|
52 | 60 |
|
53 | 61 | ```python
|
54 |
| - |
| 62 | +class Solution: |
| 63 | + def minimumDeleteSum(self, s1: str, s2: str) -> int: |
| 64 | + m, n = len(s1), len(s2) |
| 65 | + dp = [[0] * (n + 1) for _ in range(m + 1)] |
| 66 | + for i in range(1, m + 1): |
| 67 | + dp[i][0] = dp[i - 1][0] + ord(s1[i - 1]) |
| 68 | + for j in range(1, n + 1): |
| 69 | + dp[0][j] = dp[0][j - 1] + ord(s2[j - 1]) |
| 70 | + for i in range(1, m + 1): |
| 71 | + for j in range(1, n + 1): |
| 72 | + if s1[i - 1] == s2[j - 1]: |
| 73 | + dp[i][j] = dp[i - 1][j - 1] |
| 74 | + else: |
| 75 | + dp[i][j] = min(dp[i - 1][j] + ord(s1[i - 1]), |
| 76 | + dp[i][j - 1] + ord(s2[j - 1])) |
| 77 | + return dp[-1][-1] |
55 | 78 | ```
|
56 | 79 |
|
57 | 80 | ### **Java**
|
58 | 81 |
|
59 | 82 | <!-- 这里可写当前语言的特殊实现逻辑 -->
|
60 | 83 |
|
61 | 84 | ```java
|
| 85 | +class Solution { |
| 86 | + public int minimumDeleteSum(String s1, String s2) { |
| 87 | + int m = s1.length(), n = s2.length(); |
| 88 | + int[][] dp = new int[m + 1][n + 1]; |
| 89 | + for (int i = 1; i <= m; ++i) { |
| 90 | + dp[i][0] = dp[i - 1][0] + s1.codePointAt(i - 1); |
| 91 | + } |
| 92 | + for (int j = 1; j <= n; ++j) { |
| 93 | + dp[0][j] = dp[0][j - 1] + s2.codePointAt(j - 1); |
| 94 | + } |
| 95 | + for (int i = 1; i <= m; ++i) { |
| 96 | + for (int j = 1; j <= n; ++j) { |
| 97 | + if (s1.charAt(i - 1) == s2.charAt(j - 1)) { |
| 98 | + dp[i][j] = dp[i - 1][j - 1]; |
| 99 | + } else { |
| 100 | + dp[i][j] = Math.min(dp[i - 1][j] + s1.codePointAt(i - 1), dp[i][j - 1] + s2.codePointAt(j - 1)); |
| 101 | + } |
| 102 | + } |
| 103 | + } |
| 104 | + return dp[m][n]; |
| 105 | + } |
| 106 | +} |
| 107 | +``` |
| 108 | + |
| 109 | +### **C++** |
| 110 | + |
| 111 | +```cpp |
| 112 | +class Solution { |
| 113 | +public: |
| 114 | + int minimumDeleteSum(string s1, string s2) { |
| 115 | + int m = s1.size(), n = s2.size(); |
| 116 | + vector<vector<int>> dp(m + 1, vector<int>(n + 1)); |
| 117 | + for (int i = 1; i <= m; ++i) dp[i][0] = dp[i - 1][0] + s1[i - 1]; |
| 118 | + for (int j = 1; j <= n; ++j) dp[0][j] = dp[0][j - 1] + s2[j - 1]; |
| 119 | + for (int i = 1; i <= m; ++i) |
| 120 | + { |
| 121 | + for (int j = 1; j <= n; ++j) |
| 122 | + { |
| 123 | + if (s1[i - 1] == s2[j - 1]) dp[i][j] = dp[i - 1][j - 1]; |
| 124 | + else dp[i][j] = min(dp[i - 1][j] + s1[i - 1], dp[i][j - 1] + s2[j - 1]); |
| 125 | + } |
| 126 | + } |
| 127 | + return dp[m][n]; |
| 128 | + } |
| 129 | +}; |
| 130 | +``` |
62 | 131 |
|
| 132 | +### **Go** |
| 133 | +
|
| 134 | +```go |
| 135 | +func minimumDeleteSum(s1 string, s2 string) int { |
| 136 | + m, n := len(s1), len(s2) |
| 137 | + dp := make([][]int, m+1) |
| 138 | + for i := range dp { |
| 139 | + dp[i] = make([]int, n+1) |
| 140 | + } |
| 141 | + for i := 1; i <= m; i++ { |
| 142 | + dp[i][0] = dp[i-1][0] + int(s1[i-1]) |
| 143 | + } |
| 144 | + for j := 1; j <= n; j++ { |
| 145 | + dp[0][j] = dp[0][j-1] + int(s2[j-1]) |
| 146 | + } |
| 147 | + for i := 1; i <= m; i++ { |
| 148 | + for j := 1; j <= n; j++ { |
| 149 | + if s1[i-1] == s2[j-1] { |
| 150 | + dp[i][j] = dp[i-1][j-1] |
| 151 | + } else { |
| 152 | + dp[i][j] = min(dp[i-1][j]+int(s1[i-1]), dp[i][j-1]+int(s2[j-1])) |
| 153 | + } |
| 154 | + } |
| 155 | + } |
| 156 | + return dp[m][n] |
| 157 | +} |
| 158 | +
|
| 159 | +func min(a, b int) int { |
| 160 | + if a < b { |
| 161 | + return a |
| 162 | + } |
| 163 | + return b |
| 164 | +} |
63 | 165 | ```
|
64 | 166 |
|
65 | 167 | ### **...**
|
|
0 commit comments