712. Minimum ASCII Delete Sum for Two Strings 串相等的最小删除代价

int minimumDeleteSum(string& s1, string& s2) {
    int m=s1.size();
    int n=s2.size();
    vector<vector<int> > dp(m+1, vector<int>(n+1, 0));
    for(int i=0;i<n;++i)
        dp[0][i+1]=s2[i]+dp[0][i];

    for(int i=1;i<=m;++i) {
        dp[i][0]=s1[i-1]+dp[i-1][0];
        for(int j=1;j<=n;++j) {
            if (s1[i-1]==s2[j-1])
                dp[i][j]=dp[i-1][j-1];
            else
                dp[i][j]=min(dp[i-1][j]+s1[i-1], dp[i][j-1]+s2[j-1]);
        }
    }
    return dp[m][n];
}