清北学堂模拟赛d4t1 a

分析：大模拟，没什么好说的.我在考场上犯了一个超级低级的错误：while (scanf（"%s",s + 1）),导致了死循环，血的教训啊，以后要记住了.

/*
    1.没有发生改变,check一下
    2.将一位1变成0
    3.添一位
    4.减一位
*/
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>

using namespace std;

int n,len,ss[],b[];
char s[];
bool flag = false;

bool check()
{
    int res = ;
    for (int i = ;i <= n; i++)
        if (ss[i] == )
            res += i;
        if (res % (n + ) == )
            return true;
        return false;
}

bool check2()
{
    int res = ;
    for (int i = ; i <= n; i++)
        if (b[i] == )
            res += i;
        if (res % (n + ) == )
            return true;
        return false;
}

void print()
{
    for (int i = ; i <= n; i++)
        printf("%d",ss[i]);
    printf("\n");
}

void add(int x,int y)
{
    memcpy(b,ss,sizeof(ss));
    for (int i = n; i > x; i--)
        b[i] = b[i-];
        b[x] = y;
        if (check2())
        {
            memcpy(ss,b,sizeof(ss));
            flag = ;
        }
}

void eras(int x)
{
    memcpy(b,ss,sizeof(ss));
    for (int i = x; i <= n; i++)
        b[i] = b[i + ];
    if (check2())
    {
        memcpy(ss,b,sizeof(ss));
        flag = ;
    }
}

int main()
{
    scanf("%d",&n);
    while(scanf("%s",s + ) != EOF)
    {
        memset(b,,sizeof(b));
        len = strlen(s + );
        flag = false;
        if (abs(n - len) > )
        {
            printf("-1\n");
            continue;
        }
        for (int i = ; i <= len; i++)
            ss[i] = s[i] - '';
            if (n == len)
            {
        if (check())  //
        {
            print();
            continue;
        }
        for (int i = ; i <= n; i++) //
        {
            if (ss[i] == )
            {
                ss[i] = ;
                if (check())
                {
                    flag = ;
                    break;
                }
                ss[i] = ;
            }
        }
        }
        if (flag)
        {
            print();
            continue;
        }
        if (len == n - )
        {
        for (int i = ; i <= n + ; i++) //
        for (int j = ; j <= ; j++)
        {
            add(i,j); //i位以及以后都要往后挪1
            if (flag)
            break;
        }
        }
        if (flag)
        {
            print();
            continue;
        }
        if (len == n + )
        {
        for (int i = ; i <= n; i++)
        {
            eras(i);
            if (flag)
            break;
        }
        }
        if (flag)
        {
            print();
            continue;
        }
        printf("-1\n");
    }

    return ;
}