Edit Distance

class Solution {
    public:
        int editDistance(string s, string t) {
            int N = s.size(), M = t.size();
            vector < vector < int > > dp(N + 1, vector < int >(M + 1));
            for(int i = 0; i <= N; ++i)
                for(int j = 0; j <= M; ++j) {
                    if(i == 0) {
                        dp[i][j] = j;
                        continue;
                    }
                    if(j == 0) {
                        dp[i][j] = i;
                        continue;
                    }
                    if(s[i - 1] == t[j - 1])
                        dp[i][j] = dp[i - 1][j - 1];
                    else
                        dp[i][j] = min(dp[i - 1][j - 1], min(dp[i][j  - 1], dp[i - 1][j])) + 1;
                }
            return dp[N][M];
        }
};