判断STL的三种类型——UVA11995 I Can Guess the Data Structure!

http://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=497&page=show_problem&problem=3146

STL的使用，同时注意出栈出队列是的 empty判断

#include<iostream>
#include<queue>
#include<stack>
#include<stdio.h>
using namespace std;

struct data 
{
    int v;
    int k;

    friend bool operator <(data a,data b){
        return a.v<b.v;
    }
    
}s[1099];
int n;

int ceque()
{
    int i;
    queue<int>qq;
    for(i=1;i<=n;i++){
        if(s[i].k==1)qq.push(s[i].v);
        if(s[i].k==2){
            if(qq.empty()==1)return 0;
            if(qq.front()==s[i].v){
                qq.pop();continue;
            }
            else return 0;
        }
    }

    return 1;
}

int cesta()
{
    int i;
    stack<int>sta;
    for(i=1;i<=n;i++){
        if(s[i].k==1)sta.push(s[i].v);
        if(s[i].k==2){
            if(sta.empty()==1)return 0;
            if(sta.top()==s[i].v){
                sta.pop();continue;
            }
            else return 0;
        }
    }

    return 1;
}

int cepriorityq()
{
    priority_queue<data>qq;
    int i;
    for(i=1;i<=n;i++){
        if(s[i].k==1)qq.push(s[i]);
        if(s[i].k==2){
            if(qq.empty()==1)return 0;
            if(qq.top().v==s[i].v){
                qq.pop();continue;
            }
            else return 0;
        }
    }

    return 1;
}

int main()
{

    while(scanf("%d",&n)!=EOF){
        int i;
        for(i=1;i<=n;i++){
            scanf("%d%d",&s[i].k,&s[i].v);
        }

        int yq=ceque(),ys=cesta(),ypq=cepriorityq();
        if((yq+ys+ypq)>=2)printf("not sure\n");
        else if(yq)printf("queue\n");
        else if(ys)printf("stack\n");
        else if(ypq)printf("priority queue\n");
        else printf("impossible\n");
    }

    return 0;
}