LeetCode-Edit Distance-编辑距离-简单DP

https://oj.leetcode.com/problems/edit-distance/

DP例题。注意数组不要越界即可。

const int INF=9999;
class Solution {
public:
    int n,m;
    vector <vector<int>> dp;
    string s1,s2;
    int minDistance(string word1, string word2) {
        s1=word1;s2=word2;
        n=s1.length();m=s2.length();
        dp.resize(n+1,vector<int>(m+1,INF));
        dp[0][0]=0;
        for (int i=0;i<=n;i++) for (int j=0;j<=m;j++){
            if (i>0) dp[i][j]=min(dp[i][j],1+dp[i-1][j]);
            if (j>0) dp[i][j]=min(dp[i][j],1+dp[i][j-1]);
            if (i>0 && j>0) {
                if (s1[i-1]==s2[j-1]) dp[i][j]=min(dp[i][j],dp[i-1][j-1]);
                else dp[i][j]=min(dp[i][j],1+dp[i-1][j-1]);
            }
        }
        return dp[n][m];
    }
};