就是增删改几种方法嘛
递推也不难想
有点参照最长公共上升子序列的感觉

#include<bits/stdc++.h>

using namespace std;

const int N = 1117;
int n, m, f[N][N];
char a[N], b[N];

int main()
{
    cin >> n >> a + 1 >> m >> b + 1;
    for(int i = 1; i <= m; i ++) f[0][i] = i;
    for(int i = 1; i <= n; i ++) f[i][0] = i;
    for(int i = 1; i <= n; i ++)
        for(int j = 1; j <= m; j ++)
            if(a[i] == b[j]) f[i][j] = min(f[i-1][j] + 1, min(f[i][j-1] + 1, f[i-1][j-1]));
            else f[i][j] = min(f[i-1][j], min(f[i][j-1], f[i-1][j-1])) + 1;
    cout << f[n][m];
}