PAT 1014. Waiting in Line

只能说看清题意很重要，md扯了半天是开始时间在17:00之前的可以而不是结束时间。另外代码里选取最小队列的过程（move_customers内）可以用priority_queue来加速，不过反正约定的数据量不大就直接遍历吧。

#include <iostream>

#include <cstdlib>

#include <cstdio>

#include <climits>

#include <vector>

#include <list>

#include <queue>



using namespace std;



class Man {

public:

    int need;

    int time;

    int finish;

    Man(int t = 0) : time(t), finish(0), need(t) {}



};



int move_customers(list<int>& wait, vector<list<int> >& win, int win_max) {

    if (wait.size() == 0 || win_max <= 0 || win.size() <=0) {

        return 0;

    }

    int win_num = win.size();

    int moved = 0;

    int min_index = 0;

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

        if (win[i].size() < win[min_index].size()) {

            min_index = i;

        }

    }

    if (win[min_index].size() == win_max) {

        // all windows are full

        return 0;

    }

    int customer = wait.front();

    wait.pop_front();

    win[min_index].push_back(customer);

    moved++;

    return moved;

}



int time_step(vector<Man>& customers, vector<list<int> >& win, int time_elasped) {

    int win_num = win.size();

    int min_time_step = INT_MAX;

    bool has_wait = false;

    // get the mininum time step

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

        if (win[i].size() == 0) {

            continue;

        }

        has_wait = true;

        int cur = customers[win[i].front()].time;

        if (cur < min_time_step) {

            min_time_step = cur;

        }

    }

    

    time_elasped += has_wait ? min_time_step : 0;

    // time walk

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

        list<int>& cur = win[i];

        if (cur.size() == 0) {

            // win empty

            continue;

        }

        Man& man = customers[cur.front()];

        man.time  -= min_time_step;

        if (man.time == 0) {

            // this customer has been done

            man.finish = time_elasped;

            cur.pop_front();

        }

    }

    

    return time_elasped;

}





void print(int finish, int need) {

    int start = finish - need;

    int maxtime = (17 - 8) * 60;

    if (start >= maxtime) {

        printf("Sorry\n");

        return;

    }

    int hour = 8 + finish / 60;

    int min  = finish % 60;

    printf("%02d:%02d\n", hour, min);

}



int main() {



    int N, M, K, Q;

    scanf("%d%d%d%d", &N, &M, &K, &Q);

    

    vector<list<int> > win(N);

    

    list<int> wait_queue;

    vector<Man> customers;

    

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

        int time;

        scanf("%d", &time);

        customers.push_back(Man(time));

        

        wait_queue.push_back(i);

    }



    int time_elasped = 0;

    int last_time = -1;

    while (last_time != time_elasped) {

        while (move_customers(wait_queue, win, M) != 0);

        last_time = time_elasped;

        time_elasped = time_step(customers, win, last_time);

    }



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

        int qi;

        scanf("%d", &qi);

        Man& man = customers[--qi];

        print(man.finish, man.need);

    }

    



    system("pause");

    return 0;

}