hdoj1873 看病要排队

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题目：

http://acm.hdu.edu.cn/showproblem.php?pid=1873
这道题就是可以用优先队列的题，每次按优先级从大到小维护，不同的医生对应不同的队列。

编号可以从输入时就可以确定，并逐渐递增。

但有一个问题：优先级相同时，需要比较编号，先到者（小号在前）。

参考代码：

#include <iostream>#include <cstdio>#include <cstring>#include <algorithm>#include <string>using namespace std;const int N = 2000+10;int n;struct node {    int ID;//ID号;    int prior;//优先级;};node heap1[N],heap2[N],heap3[N];int sz1,sz2,sz3;void init() {    memset(heap1,0,sizeof(heap1));    memset(heap2,0,sizeof(heap2));    memset(heap3,0,sizeof(heap3));    sz1 = sz2 = sz3 = 0;}void push(node heap[],int b,int id,int &sz) {    int i = sz++;    while (i > 0) {        int p = (i - 1) / 2;        if (heap[p].prior > b || (heap[p].prior == b && heap[p].ID < id)) break;        heap[i].prior = heap[p].prior;        heap[i].ID = heap[p].ID;        i = p;    }    heap[i].prior = b;    heap[i].ID = id;}void pop(node heap[],int &sz) {    int x = heap[--sz].prior;    int id = heap[sz].ID;    int i = 0;    while (i * 2 + 1 < sz) {        int a = i * 2 + 1;        int b = i * 2 + 2;        if (b < sz && ((heap[a].prior < heap[b].prior) || (heap[a].prior == heap[b].prior && heap[a].ID > heap[b].ID))) {            a = b;        }        if (heap[a].prior < x || (heap[a].prior == x && heap[a].ID > id)) break;        heap[i].prior = heap[a].prior;        heap[i].ID = heap[a].ID;        i = a;    }    heap[i].prior = x;    heap[i].ID = id;}int main() {    while (scanf("%d", &n) != EOF) {        string s;        int a,b;        int id = 1;        init();        for (int i = 1;i <= n;++i) {            cin >> s;            if (s == "IN") {                scanf("%d%d", &a, &b);                if (a == 1) {                    push(heap1,b,id,sz1);                    //cout << sz1 << endl;                    id++;                }                if (a == 2) {                    push(heap2,b,id,sz2);                    id++;                }                       if (a == 3) {                    push(heap3,b,id,sz3);                    id++;                }                           }            else {                scanf("%d", &a);                if (a == 1) {                    if (sz1 == 0) printf("EMPTY\n");                    else {                        printf("%d\n", heap1[0].ID);                        pop(heap1,sz1);                    }                }                if (a == 2) {                    if (sz2 == 0) printf("EMPTY\n");                    else {                        printf("%d\n", heap2[0].ID);                        pop(heap2,sz2);                    }                }                               if (a == 3) {                    if (sz3 == 0) printf("EMPTY\n");                    else {                        printf("%d\n", heap3[0].ID);                        pop(heap3,sz3);                    }                }                           }        }    }    return 0;}

当然，这道题也可以用标准库解决。

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