1、實(shí)驗(yàn)五 C+模擬LRU頁(yè)面置換算法一、實(shí)驗(yàn)?zāi)康模河胏+模擬LRU頁(yè)面置換算法二、實(shí)驗(yàn)內(nèi)容：隨機(jī)一訪問(wèn)串和駐留集的大小，通過(guò)模擬程序顯示淘汰的頁(yè)號(hào)并統(tǒng)計(jì)命中率。示例：輸入訪問(wèn)串：7 0 1 2 0 3 0 4 2 3 0 3 2 1 2 0 1 駐留集大小：3算法的實(shí)現(xiàn)：由于LRU算法淘汰的是上次使用距離t時(shí)刻最遠(yuǎn)的頁(yè)，故需記錄這個(gè)距離。計(jì)數(shù)器：可使用計(jì)數(shù)器，給每一個(gè)頁(yè)幀增設(shè)一個(gè)計(jì)數(shù)器。每訪問(wèn)一頁(yè)，就把對(duì)應(yīng)頁(yè)幀的計(jì)數(shù)器清零，其余頁(yè)幀的計(jì)數(shù)器加1.因此，計(jì)數(shù)器值為最大的頁(yè)即上次訪問(wèn)距當(dāng)前最遠(yuǎn)的頁(yè)。7 0 1 2 0 3 0 4 2 3 0 3 2 0/7 1/7 2/7 0/2 1/2 2/2 3

2、/2 0/4 1/4 2/4 0/0 1/0 2/0 0/0 1/0 2/0 0/0 1/0 0/0 1/0 2/0 0/3 1/3 0/31/3 0/1 1/1 2/1 0/3 1/3 2/3 0/2 1/2 2/2 3/2 0/2缺 缺 缺 缺 命 缺 命 缺 缺 缺 缺 命 命 紅色表示：每個(gè)頁(yè)幀對(duì)應(yīng)的計(jì)數(shù)器值通過(guò)模擬程序輸出淘汰的頁(yè)號(hào)分別為：7 1 2 3 0 4 命中率為：4/134、 代碼：#include using namespace std;struct node char data; int time;void init(char str,int n,struct node

3、 zhuliuji,int m) for(int i = 0;im;i+) zhuliujii.data = 0; zhuliujii.time = 0; for(int i =0;istri; void addtime(struct node zhuliuji,int m) for(int i=0;im;i+) zhuliujii.time+; char addzhuliuji(struct node zhuliuji,int m,char c) char ch = 0; int max = zhuliuji0.time; int temp = 0; /標(biāo)記時(shí)間最長(zhǎng)的駐留級(jí) for(int

4、i=0;im;i+) if(maxzhuliujii.time&zhuliujii.data!=c) max = zhuliujii.time; temp = i; if(zhuliujii.data=c) zhuliujii.time =0; / coutzhuliuji存在cendl; return ch; ch = zhuliujitemp.data; zhuliujitemp.data = c; zhuliujitemp.time = 0; return ch;void LRU(char str,int n,struct node zhuliuji,int m) int jtemp=0

5、; for(int i =0;in;i+) if(im) zhuliujijtemp.data = stri; addtime(zhuliuji,m); zhuliujijtemp.time = 0; jtemp +; else addtime(zhuliuji,m); char ch = addzhuliuji(zhuliuji,m,stri); / if(ch!=0) /cout淘汰的頁(yè)數(shù)為：chendl; cout駐留級(jí)為：; for(int j=0;jm;j+) coutzhuliujij.datat; coutjtemp; /顯示結(jié)果，以便觀察int main() struct node zhuliuji20; char str20; int n,m; cout請(qǐng)輸入訪問(wèn)串的大?。簄; cout請(qǐng)輸入駐留級(jí)大?。簃;