实验作业

先来先服务调度算法。

最短作业优先调度算法。

最高响应比优先调度算法。

#include<bits/stdc++.h> 


#include <iostream>
#include <cstring>
#include <cstdio>
#include <thread>
#include <string>
#include <algorithm>

using namespace std;

const int maxn = 1e5 + 7, inf = 1e9 + 7;

struct JOB {
    string name;
    int start;
    int runtime;
}x[maxn];
int n, t;

bool FCFSsort(JOB a, JOB b) {
    return a.start < b.start;
}

bool SJFsort(JOB a, JOB b) {
    if (a.runtime == b.runtime)
        return a.start < b.start;
    return a.runtime < b.runtime;
}

bool HRRNsort(JOB a, JOB b) {
    if (t >= a.start || t >= b.start)
        return (t - a.start) / a.runtime > (t - b.start) / b.runtime;
    else
        return a.start > b.start;
}

void FCFS() {
    double tat = 0, taw = 0;
    sort(x, x + n, FCFSsort);
    cout << "调度过程：\n进程名    运行开始时间    运行结束时间    周转时间" << endl;
    for (int i = 0, t = 0; i < n; i++) {
        t = max(x[i].start, t);
        cout << x[i].name;
        printf("    %8d    %8d    %8d\n", t, t + x[i].runtime, t + x[i].runtime - x[i].start);
        // cout << x[i].name << "    " << t << "            " << t + x[i].runtime << endl;
        t += x[i].runtime;
        tat += (t - x[i].start);
        taw += (double)(t - x[i].start) / x[i].runtime;
    }
    printf("平均周转时间为:%.3f\n平均带权周转时间为:%.3f\n\n", tat / n, taw / n);
}

void SJF() {
    double tat = 0, taw = 0;
    sort(x, x + n, SJFsort);
    cout << "调度过程：\n进程名    运行开始时间    运行结束时间    周转时间" << endl;
    for (int i = 0, t = 0; i < n; i++) {
        if (t < x[i].start)//不中断，在最短作业未进入时，选择较小的已经进入的进程，若无则选择最先进程
        {
            int mint = x[i].start;
            for (int j = i + 1; j < n; j++) {
                if (x[j].start < t) {
                    mint = x[j].start;
                    break;
                }
                else if (x[j].start < mint)
                    mint = x[j].start;
                swap(x[i], x[j]);
            }
        }

        t = max(x[i].start, t);
        cout << x[i].name;
        printf("    %8d    %8d    %8d\n", t, t + x[i].runtime, t + x[i].runtime - x[i].start);
        // cout << x[i].name << "    " << t << "            " << t + x[i].runtime << endl;
        t += x[i].runtime;
        tat += (t - x[i].start);
        taw += (double)(t - x[i].start) / x[i].runtime;
    }
    printf("平均周转时间为:%.3f\n平均带权周转时间为:%.3f\n\n", tat / n, taw / n);
}

void HRRN() {
    t = 0;
    double tat = 0, taw = 0;
    sort(x, x + n, HRRNsort);
    cout << "调度过程：\n进程名    运行开始时间    运行结束时间    周转时间" << endl;
    for (int j = 0, i = 0; j < n; j++) {
        t = max(x[i].start, t);
        cout << x[i].name;
        printf("    %8d    %8d    %8d\n", t, t + x[i].runtime, t + x[i].runtime - x[i].start);
        // cout << x[i].name << "    " << t << "            " << t + x[i].runtime << endl;
        t += x[i].runtime;
        tat += (t - x[i].start);
        taw += (double)(t - x[i].start) / x[i].runtime;
        x[i].start = inf;
        sort(x, x + n, HRRNsort);
    }
    printf("平均周转时间为:%.3f\n平均带权周转时间为:%.3f\n\n", tat / n, taw / n);
}
int main() {
    //     freopen("input.txt", "r", stdin);
    //     freopen("output.txt", "w", stdout);
    cout << "需要创建几个进程？" << endl;
    cin >> n;
    cout << "请按照以下格式创建进程\n进程名    创建时间    执行时间" << endl;
    for (int i = 0; i < n; i++) {
        cin >> x[i].name >> x[i].start >> x[i].runtime;
    }
    cout << "创建成功!" << endl << endl;
    cout << "    先来先服务调度算法（FCFS）：" << endl;
    FCFS();
    cout << "    短作业优先调度算法（SJF）：" << endl;
    SJF();
    cout << "    高相应比优先调度算法（HRRN）：" << endl;
    HRRN();
}
/*
3
1 8 2
2 9 1
3 10 1
*/