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;
}