看病要排队

7 IN 1 1 IN 1 2 OUT 1 OUT 2 IN 2 1 OUT 2 OUT 1 2 IN 1 1 OUT 1 Sample Output
2 EMPTY 3 1 1
重新理解拉优先队列，很水的了代码很好理解
#include<cstdio>#include<queue>#include<stack>#include<algorithm>using namespace std;struct node{    int a, b;    friend bool Operator < (node x, node y) {        if(x.b == y.b) {            return x.a > y.a;        }        else {            return x.b < y.b;        }    }}; int main(){    int n;    while(~scanf("%d",&n)) {        char str[10];        node p;        int a, b;        int k = 1;        priority_queue<node> fq_1,fq_2,fq_3;        for(int i = 0; i< n; i++) {            scanf("%s",str);            if(str[0] == 'I') {            scanf("%d%d",&a,&b);                if(a == 1) {                    p.a = k;                    k++;                    p.b = b;                    fq_1.push(p);                }                if(a == 2) {                    p.a = k;                    k++;                    p.b = b;                    fq_2.push(p);                }                if(a == 3) {                    p.a = k;                    k++;                    p.b = b;                    fq_3.push(p);                }            }            else {                scanf("%d",&a);                if(a == 1) {                    if(fq_1.empty())                     printf("EMPTY/n");                    else {                    printf("%d/n",fq_1.top());                    fq_1.pop();                    }                }                if(a == 2) {                    if(fq_2.empty())                     printf("EMPTY/n");                    else {                    printf("%d/n",fq_2.top());                    fq_2.pop();                    }                }                if(a == 3) {                    if(fq_3.empty())                     printf("EMPTY/n");                    else {                    printf("%d/n",fq_3.top());                    fq_3.pop();                    }                }            }        }    }}