LRU PROGRAM - Slip 3_1,8_1,12_1,18
#include <stdio.h>
int findLRU(int time[], int n) {
int i, min = time[0], pos = 0;
for (i = 1; i < n; i++)
if (time[i] < min) pos = i, min = time[i];
return pos;
int main() {
int pages[] = {3, 5, 7, 2, 5, 1, 2, 3, 1, 3, 5, 3, 1, 6, 2}, frames[3], time[3];
int n = 15, no_of_frames = 3, count = 0, faults = 0, i, j, pos;
for (i = 0; i < no_of_frames; i++) frames[i] = -1;
for (i = 0; i < n; i++) {
int flag = 0;
for (j = 0; j < no_of_frames; j++)
if (frames[j] == pages[i]) flag = 1, time[j] = ++count;
if (!flag) {
pos = (frames[0] == -1) ? i % no_of_frames : findLRU(time, no_of_frames);
frames[pos] = pages[i], time[pos] = ++count, faults++;
for (j = 0; j < no_of_frames; j++) printf("%d ", frames[j] == -1 ? -1 : frames[j]);
printf("\n");
printf("\nTotal Page Faults: %d\n", faults);
return 0;
}
Optimal Page Replacement - Slip 5_1,7_1,17_1,23_2
#include <stdio.h>
int find_farthest(int pages[], int n, int frame[], int m, int index) {
for (int i = 0; i < m; i++) {
int j;
for (j = index; j < n; j++)
if (frame[i] == pages[j]) break;
if (j == n) return i;
return 0;
int main() {
int pages[] = {8, 5, 7, 8, 5, 7, 2, 3, 7, 3, 5, 9, 4, 6, 2};
int n = sizeof(pages) / sizeof(pages[0]), m, frame[10], faults = 0, filled = 0;
printf("Enter number of frames: ");
scanf("%d", &m);
for (int i = 0; i < m; i++) frame[i] = -1;
for (int i = 0; i < n; i++) {
int hit = 0;
for (int j = 0; j < m; j++)
if (frame[j] == pages[i]) hit = 1;
if (!hit) {
if (filled < m) frame[filled++] = pages[i];
else frame[find_farthest(pages, n, frame, m, i + 1)] = pages[i];
faults++;
printf("Page %d -> ", pages[i]);
for (int j = 0; j < m; j++) printf("%d ", frame[j]);
printf("\n");
printf("\nTotal Page Faults: %d\n", faults);
return 0;
