poj 3158 Kickdown 字符串匹配？

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <iostream>
#include <algorithm>
#include <cmath>
#include <set>
#include <queue>
#include <stack>
#include <map>
#include <vector>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> P;

const int maxn = 310;


int main()
{
    //freopen("in.txt", "r", stdin);
    //freopen("out.txt", "w", stdout);

    char a[maxn], b[maxn], c[maxn];
    while(scanf("%s%s", a, b) == 2)
    {
        int alen = strlen(a);
        int blen = strlen(b);

        if(alen < blen)
        {
            swap(a, b);
            swap(alen, blen);
        }
        int clen = 2*blen + alen;

        fill(c, c + blen, ‘1‘);
        strncpy(c+blen, a, alen);
        fill(c + blen + alen,c + 2*blen + alen, ‘1‘);

        int ans = alen + blen;
        for(int j = 0; j < clen-blen; j++)
        {
            bool flag = true;
            int tmp;

            for(int i = 0; i < blen && flag; i++)
            {
                if(c[j+i] - ‘0‘ + b[i] - ‘0‘ > 3)
                    flag = false;
            }

            if(flag)
            {
                if(blen <= j && j <= alen)
                {
                    ans = alen;
                    break;
                }
                else if(j < blen)
                {
                    tmp = alen + blen - j;
                    if(tmp < ans)
                        ans = tmp;
                }
                else if(j > alen)
                {
                    tmp = j;
                    if(tmp < ans)
                        ans = tmp;
                }
            }
        }

        printf("%d\n", ans);

    }


    return 0;
}