建立自己的代码风格比建立自己的思想体系更加困难，就像思考的时候习惯从0开始和从1开始的差异会导致好多步骤不一样。这个代码模仿kuangbin大佬
链接如下 https://www.cnblogs.com/kuangbin/p/3164106.html

#include <bits/stdc++.h>
using namespace std;
const int N = 1e5+10,INF = 0x3f3f3f3f;
char str[N];
int dp[1010][1010];
int getid(char c)
{
    if(c == 'A') return 0;
    if(c == 'C') return 1;
    if(c == 'G') return 2;
    if(c == 'T') return 3;
}
struct Trie{
    int nxt[N][4],fail[N],end[N];
    int rt,tot;
    int newnode()
    {
        for(int i = 0; i < 26; ++i) nxt[tot][i] = -1;
        end[tot] = 0;
        return tot++;
    }
    void init()
    {
        tot = 0;
        rt = newnode();
    }
    void insert(char *str)
    {
        int p = rt;
        for(int i = 0; str[i]; ++i)
        {
            if(nxt[p][getid(str[i])] == -1) nxt[p][getid(str[i])] = newnode();
            p = nxt[p][getid(str[i])];
        }
        end[p] = 1;
    }
    void build()
    {
        queue<int> q;
        fail[rt] = rt;
        for(int i = 0; i < 4; ++i)
            if(nxt[rt][i] == -1) nxt[rt][i] = rt;
            else
            {
                fail[nxt[rt][i]] = rt;
                q.push(nxt[rt][i]);
            }
        while(!q.empty())
        {
            int fa = q.front(); q.pop();
            if(end[fail[fa]]) end[fa] = 1;
            for(int i = 0; i < 4; ++i)
                if(nxt[fa][i] == -1) nxt[fa][i] = nxt[fail[fa]][i];
                else
                {
                    fail[nxt[fa][i]] = nxt[fail[fa]][i];
                    q.push(nxt[fa][i]);
                }
        }
    }
    int solve(char *str)
    {
        int len = strlen(str);

        for(int i = 0; i <= len; ++i)
            for(int j = 0; j < tot; ++j) dp[i][j] = INF;
        dp[0][rt] = 0;
        for(int i = 0; str[i]; ++i)
            for(int j = 0; j < tot; ++j)
            {
                if(dp[i][j] >= INF) continue;
                for(int k = 0; k < 4; ++k)
                {
                    if(end[nxt[j][k]]) continue;
                    dp[i+1][nxt[j][k]] = min(dp[i+1][nxt[j][k]],dp[i][j]+(getid(str[i])==k?0:1));
                }
            }
        int ans = INF;
        for(int j = 0; j < tot; ++j) ans = min(ans,dp[len][j]);
        if(ans == INF) return -1; 
        return ans;
    }
}ac;
int main()
{
    int n;
    int cas = 0;
    while(cin >> n && n)
    {
        ac.init();
        for(int i = 0; i < n; ++i)
        {
            scanf("%s",str);
            ac.insert(str);
        }
        ac.build();
        scanf("%s",str);
        printf("Case %d: %d\n",++cas,ac.solve(str));
    }
}