hdu 5055

http://acm.hdu.edu.cn/showproblem.php?pid=5055

n个digit能组合出的最大无前导0奇数

无聊的模拟

#include <cstdio>

#include <cstdlib>

#include <cmath>

#include <cstring>

#include <string>

#include <queue>

#include <vector>

#include<set>

#include <iostream>

#include <algorithm>

using namespace std;

#define RD(x) scanf("%d",&x)

#define RD2(x,y) scanf("%d%d",&x,&y)

#define clr0(x) memset(x,0,sizeof(x))

typedef long long LL;

int s[105];

bool vis[105];

void work(int n)

{

    clr0(vis);

    for(int i = 0;i < n;++i)

        RD(s[i]);

    sort(s,s+n);

    bool flag = false;

    int last;

    for(int i = 0;i < n;++i){

        if(s[i]&1){

            vis[i] = true;

            flag = true;

            last = s[i];

            break;

        }

    }

    if(!flag){

        puts("-1");

        return;

    }

    if(n == 1){

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

        return;

    }

    flag = false;

    for(int i = n-1;i >= 0;--i){

        if(!vis[i]){

            if(s[i] == 0)

                flag = true;

            else

                flag = false;

            break;

        }

    }

    if(flag){

        puts("-1");

        return;

    }

    for(int i = n - 1;i >= 0;--i)if(!vis[i]){

        printf("%d",s[i]);

    }

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

    return;

}

int main() {

    int n;

    while(~RD(n)){

        work(n);

    }

    return 0;

}