C++編寫的頁面淘汰算法FIFO
C++編寫的頁面淘汰算法FIFO
//FIFOinclude<iomanip>
include<iostream>
using namespace std; void discard(int Array[][19],int pagenumber[],int page[],int max); int FIFO(int pagenumber[],int order); int main() { int Array[4][19]; int page[19] = {7,0,1,2,0,3,0,4,2,3,0,3,2,1,2,0,1,7,0}; int pagenumber[3] = {-1,-1,-1}; //請求求頁面序列 cout<<"請求頁面訪問序列為:"<<endl; for(int i = 0;i < 19;i++){ Array[3][i] = -1;
cout<<setw(3)<<page[i]; } int max = 19; discard( Array, pagenumber,page,max); cout<<endl; cout<<endl; //輸出 cout<<"輸出結果如下表(-2)代表沒有缺頁中斷!"<<endl; int LackPageNumber = 0; for(int j = 0; j < 4;j++){ for(int k = 0; k < 19;k++){ cout<<setw(3)<<Array[j][k]; if(j == 3){ if(Array[j][k] != -2) LackPageNumber++; } } cout<<endl; } cout<<"缺頁次數:"<<LackPageNumber<<endl; return 0; } void discard(int Array[][19],int pagenumber[],int page[],int n) { for(int tt = 0;tt < n;tt++){ if(FIFO(pagenumber,page[tt])> -1){ Array[0][tt] = pagenumber[0]; Array[1][tt] = pagenumber[1]; Array[2][tt] = pagenumber[2]; Array[3][tt] = -2;//表示非缺頁 } else{ Array[0][tt] = page[tt]; Array[1][tt] = pagenumber[0]; Array[2][tt] = pagenumber[1]; Array[3][tt] =-1; for(int ii = 2;ii >0;ii--){ pagenumber[ii] = pagenumber[ii-1]; } pagenumber[0] =page[tt]; } } } int FIFO(int pagenumber[],int order) { if(pagenumber[0] == order) return 0; else if(pagenumber[1] == order) return 1; else if(pagenumber[2] == order) return 2; else return -1; }</pre>