Shuffle'm Up POJ 3087

http://acm.hust.edu.cn/vjudge/contest/121377#problem/G 

根据题意模拟即可

#include<stdio.h>
#include<string.h>
#include<math.h>
#include<queue>
using namespace std;

#define maxn 300

char a[maxn*maxn], b[maxn*maxn], s1[maxn], s2[maxn], s[maxn*maxn];

int solve(int n, int step)
{
    int j=0;

    for(int i=0; i<n; i++)
    {
        a[j++] = s2[i];
        a[j++] = s1[i];
    }

    a[j]='';

    if(!strcmp(a, s)) return step;

    if(step == 1) strcpy(b, a);

    if(step!=1 && !strcmp(b, a)) return -1;

    strncpy(s1, a, n);
    strncpy(s2, a+n, n);

    return solve(n, step+1);
}

int main()
{
    int T, t=1, n;
    scanf("%d", &T);

    while(T --)
    {
        scanf("%d %s %s %s", &n, s1, s2, s);

        int ans = solve(n, 1);

        printf("%d %d
",t++, ans);
    }
    return 0;
}