快期末了在複習作業系統，順便把實驗課上寫的演算法重新寫一遍

先來先服務演算法非常簡單，當作業來了，先來先執行，後來的按到達時間的先後排在就緒佇列上，每次取隊首元素執行。

實驗環境是WIN7 64位+Visual Studio 2015

//main.cpp
#include "FCFS.h"

int main()
{
	std::vector<PCB> PCBList;

	//輸入作業資訊
	InputPCB(PCBList);

	//FCFS演算法
	FCFS(PCBList);

	//顯示結果
	show(PCBList);

	return 0;
}

//FCFS.h
#ifndef FCFS_H_
#define FCFS_H_

#include <iostream>
#include <iomanip>
#include <vector>
#include <queue>

//作業結構體
typedef struct PCB
{
	int ID;							//識別符號
	int ComeTime;					//到達時間
	int ServerTime;					//服務時間
	int FinishTime;					//完成時間
	int TurnoverTime;				//週轉時間
	double WeightedTurnoverTime;	//帶權週轉時間
}PCB;

/*
函式功能：輸入作業資訊
引數說明：
PCBList		std::vector<PCB>&		PCB鏈
*/
void InputPCB(std::vector<PCB> &PCBList);

/*
函式功能：FCFS演算法
引數說明：
PCBList		std::vector<PCB>&		PCB鏈
*/
void FCFS(std::vector<PCB> &PCBList);

/*
函式功能：顯示結果
引數說明：
PCBList		std::vector<PCB>&		PCB鏈
*/
void show(std::vector<PCB> &PCBList);

/*
函式功能：比較函式，用於sort()，按ComeTime升序排列
引數說明：
p1			const PCB&				PCB
p2			const PCB&				PCB
*/
bool cmp(const PCB &p1, const PCB &p2);

#endif

//FCFS.cpp
#include "FCFS.h"

void InputPCB(std::vector<PCB> &PCBList)
{
	do {
		PCB temp;
		std::cout << "輸入識別符號: ";
		std::cin >> temp.ID;
		std::cout << "輸入到達時間: ";
		std::cin >> temp.ComeTime;
		std::cout << "輸入服務時間: ";
		std::cin >> temp.ServerTime;
		PCBList.push_back(temp);

		std::cout << "繼續輸入？Y/N: ";
		char ans;
		std::cin >> ans;
		if ('Y' == ans || 'y' == ans)
			continue;
		else
			break;
	} while (true);
}

void FCFS(std::vector<PCB> &PCBList)
{
	std::sort(PCBList.begin(), PCBList.end(), cmp);		//按升序排列ComeTime
	int FinishTime = -1;								//上一個作業的完成時間
	for (std::vector<PCB>::iterator it = PCBList.begin(); it < PCBList.end(); ++it)
	{
		if ((*it).ComeTime < FinishTime)				//作業到達時，上一個作業還沒有結束
			(*it).FinishTime = (*(it - 1)).FinishTime + (*it).ServerTime;
		else
			(*it).FinishTime = (*it).ComeTime + (*it).ServerTime;
		(*it).TurnoverTime = (*it).FinishTime - (*it).ComeTime;
		(*it).WeightedTurnoverTime = (double)(*it).TurnoverTime / (*it).ServerTime;
		FinishTime = (*it).FinishTime;
	}
}

void show(std::vector<PCB> &PCBList)
{
	int SumTurnoverTime = 0;
	double SumWeightedTurnoverTime = 0;

	std::cout.setf(std::ios::left);

	std::cout << std::setw(20) << "識別符號";
	for (std::vector<PCB>::iterator it = PCBList.begin(); it < PCBList.end(); ++it)
		std::cout << std::setw(5) << (*it).ID;
	std::cout << std::endl;

	std::cout << std::setw(20) << "到達時間";
	for (std::vector<PCB>::iterator it = PCBList.begin(); it < PCBList.end(); ++it)
		std::cout << std::setw(5) << (*it).ComeTime;
	std::cout << std::endl;

	std::cout << std::setw(20) << "服務時間";
	for (std::vector<PCB>::iterator it = PCBList.begin(); it < PCBList.end(); ++it)
		std::cout << std::setw(5) << (*it).ServerTime;
	std::cout << std::endl;

	std::cout << std::setw(20) << "完成時間";
	for (std::vector<PCB>::iterator it = PCBList.begin(); it < PCBList.end(); ++it)
		std::cout << std::setw(5) << (*it).FinishTime;
	std::cout << std::endl;

	std::cout << std::setw(20) << "週轉時間";
	for (std::vector<PCB>::iterator it = PCBList.begin(); it < PCBList.end(); ++it)
	{
		std::cout << std::setw(5) << (*it).TurnoverTime;
		SumTurnoverTime += (*it).TurnoverTime;;
	}
	std::cout << std::endl;

	std::cout << std::setw(20) << "帶權週轉時間";
	for (std::vector<PCB>::iterator it = PCBList.begin(); it < PCBList.end(); ++it)
	{
		std::cout << std::setw(5) << (*it).WeightedTurnoverTime;
		SumWeightedTurnoverTime += (*it).WeightedTurnoverTime;;
	}
	std::cout << std::endl;

	std::cout << "平均週轉時間: " << (double)SumTurnoverTime / PCBList.size() << std::endl;
	std::cout << "平均帶權週轉時間: " << SumWeightedTurnoverTime / PCBList.size() << std::endl;
}

bool cmp(const PCB &p1, const PCB &p2)
{
	return p1.ComeTime < p2.ComeTime;
}