先进先出页面置换算法

#includestdio.h#defineM20//要访问的页面数#defineN3//内存容量voidFIFO(inta[N],intb[M]){inti,j,k;intc[M]={0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};floats;for(i=0;iN;i++){a[i]=b[i];for(j=0;j=i;j++){printf(%d,a[j]);}printf(\n);printf(\n);printf(内存中的页面为：);for(j=0;j=i;j++){printf(%d,a[j]);}printf(\n);printf(\n);}k=N;for(j=N;jM;j++){for(i=0;iN;i++)if(b[j]==a[i]){printf(内存中有%d页面，可直接访问。\n,b[j]);c[j]=1;break;}if(c[j]==1){for(i=0;iN;i++)printf(%d,a[i]);}if(c[j]==0){a[k%N]=b[j];k++;for(i=0;iN;i++)printf(%d,a[i]);printf(\n);printf(页面%d进入内存\n,b[j]);}printf(\n);}s=k*1.0/M;printf(中断次数为：%d\n,k);printf(缺页率为：%f\n,s);}voidmain(){inti;inta[N]={0,0,0};intb[M];printf(\nFIFO页面置换算法\n);printf(\n);printf(输入要访问的页面：);for(i=0;iM;i++){scanf(%d,&b[i]);if(b[i]==-1)break;}FIFO(a,b);}