51Nod 1109 01组成N的倍数

#include <iostream>
#include <fstream>
#include <sstream>
#include <cstdlib>
#include <cstdio>
#include <cmath>
#include <string>
#include <cstring>
#include <algorithm>
#include <queue>
#include <stack>
#include <vector>
#include <set>
#include <map>
#include <iomanip>
#include <cctype>
#include <cassert>
#include <bitset>
#include <ctime>

using namespace std;

#define pau system("pause")
#define ll long long
#define pii pair<int, int>
#define pb push_back
#define mp make_pair
#define clr(a, x) memset(a, x, sizeof(a))

const double pi = acos(-1.0);
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 7;
const double EPS = 1e-9;

struct gg {
    string s;
    int a;
    gg(){}
    gg(string s, int a) : s(s), a(a) {}
};
bool vis[1000015];
queue<gg> que;
int n;
int main() {
    scanf("%d", &n);
    if (1 == n) {
        printf("1");
        return 0;
    }
    que.push(gg("1", 1 % n));
    vis[1] = 1;
    while (que.size()) {
        gg g = que.front(); que.pop();
        for (int i = 0; i < 2; ++i) {
            string s = g.s + (char)(‘0‘ + i);
            int a = (g.a * 10 + i) % n;
            if (!a) {
                cout << s;
                return 0;
            }
            if (vis[a]) continue;
            que.push(gg(s, a)); vis[a] = 1;
        }
    }
    return 0;
}