712

class Solution {
public:
    int minimumDeleteSum(string s1, string s2) {
        int n=s1.size(), m=s2.size();
        int dp[n+1][m+1];
        memset(dp, 0, sizeof dp);
        for(int i=1; i<=n; i++)
            dp[i][0] = dp[i-1][0]+int(s1[i-1]);
        for(int i=1; i<=m; i++)
            dp[0][i] = dp[0][i-1]+int(s2[i-1]);

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