712.cpp

class Solution {
  // Runtime: 32 ms, faster than 56.31% of C++ online submissions for Minimum
  // ASCII Delete Sum for Two Strings. Memory Usage: 17.7 MB, less than 29.97%
  // of C++ online submissions for Minimum ASCII Delete Sum for Two Strings.
public:
  int minimumDeleteSum(string s1, string s2) {
    vector<vector<int>> dp(s1.size() + 1, vector<int>(s2.size() + 1));
    for (int i = 1; i <= s1.size(); ++i)
      dp[i][0] = dp[i - 1][0] + s1[i - 1];
    for (int i = 1; i <= s2.size(); ++i)
      dp[0][i] = dp[0][i - 1] + s2[i - 1];
    for (int i = 1; i <= s1.size(); ++i)
      for (int j = 1; j <= s2.size(); ++j) {
        if (s1[i - 1] == s2[j - 1])
          dp[i][j] = dp[i - 1][j - 1];
        else
          dp[i][j] = min({dp[i][j - 1] + s2[j - 1],
                          dp[i - 1][j - 1] + s1[i - 1] + s2[j - 1],
                          dp[i - 1][j] + s1[i - 1]});
      }
    return dp[s1.size()][s2.size()];
  }
};