#include <iostream>#include <vector>#include <stdlib.h>#include <algorithm>using namespace std;/********************题目要求***********************************最短左右优先，输出总等待时间测试用例：任务：    A，B，C，D请求时间：0，2，4，5持续时间：7，4，1，4求平均等待时间****************************************************************//********************解题思路***********************************            请求时间   持续时间  开始时间  结束时间   等待时间 = 开始时间 - 请求时间A        0          7         0         7           0----------------------------------------------------------C        4          1         7         8           3----------------------------------------------------------B        2          4         8         12          6----------------------------------------------------------D        5          4         12        16          7****************************************************************/void show(vector<int> &time){    for (int i = 0; i < time.size(); i++)        cout << time[i] << "   ";}float average_time(vector<int> &require_time, vector<int> &duration_time, int n){    for (int i = 0; i < n - 1; i++)    {        for (int j = i + 1; j < n; j++)        {            if ((duration_time[i] > duration_time[j]) || ((duration_time[i] == duration_time[j]) && (require_time[i] > require_time[j])))            {                duration_time[i] = duration_time[i] ^ duration_time[j];                duration_time[j] = duration_time[i] ^ duration_time[j];                duration_time[i] = duration_time[i] ^ duration_time[j];                 require_time[i] = require_time[i] ^ require_time[j];                require_time[j] = require_time[i] ^ require_time[j];                require_time[i] = require_time[i] ^ require_time[j];            }        }    }    int min = 0xFFFFFFFF, count = 0;    vector<int> start_time(n), end_time(n),wait_time(n);    int sum = 0;    for (int i = 0; i < require_time.size(); i++)    {        if (require_time[i] < min)        {            min = require_time[i];            count = i;        }        else if (min == require_time[i])        {            count = duration_time[count] < duration_time[i] ? duration_time[count] : duration_time[i];        }    }    duration_time.insert(duration_time.begin(), duration_time[count]);    duration_time.erase(duration_time.begin()+ count + 1);    require_time.insert(require_time.begin(), require_time[count]);    require_time.erase(require_time.begin() + count + 1);    start_time[0] = require_time[0];    end_time[0] = duration_time[0];    wait_time[0] = 0;    for (int i = 1; i < n; i++)    {        start_time[i] = end_time[i - 1];        end_time[i] = start_time[i] + duration_time[i];        wait_time[i] = start_time[i] - require_time[i];        sum += wait_time[i];    }    return (float)(sum / n);}int main(){    int task_list = 0;    cin >> task_list;    vector<int> require_time, duration_time;    int time0 = 0, time1 = 0;    int temp = task_list;    while (temp--)    {        cin >> time0 >> time1;        require_time.push_back(time0);        duration_time.push_back(time1);    }    cout << average_time(require_time, duration_time, task_list) << endl;        system("pause");}