Create ADR.c

Miscellaneous Algorithms/Adaptive Disk Reordering Algorithm/ADR.c

@@ -0,0 +1,79 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+#define MAX_REQUESTS 100
+
+// Structure to store each disk request with track number and status
+typedef struct {
+    int track;
+    int is_serviced;
+} DiskRequest;
+
+// Function to calculate absolute difference
+int abs_diff(int a, int b) {
+    return a > b ? a - b : b - a;
+}
+
+// Function to reorder requests dynamically based on current disk position
+void reorder_requests(DiskRequest requests[], int num_requests, int current_head) {
+    for (int i = 0; i < num_requests - 1; i++) {
+        for (int j = i + 1; j < num_requests; j++) {
+            // Sort requests based on proximity to current head position
+            if (abs_diff(requests[i].track, current_head) > abs_diff(requests[j].track, current_head)) {
+                DiskRequest temp = requests[i];
+                requests[i] = requests[j];
+                requests[j] = temp;
+            }
+        }
+    }
+}
+
+// Adaptive Disk Reordering (ADR) algorithm implementation
+void adaptive_disk_reordering(DiskRequest requests[], int num_requests, int initial_head) {
+    int current_head = initial_head;
+    int total_seek_time = 0;
+
+    printf("Seek Sequence: %d", current_head);
+
+    for (int i = 0; i < num_requests; i++) {
+        reorder_requests(requests, num_requests, current_head);
+
+        // Find the nearest unserviced request
+        for (int j = 0; j < num_requests; j++) {
+            if (!requests[j].is_serviced) {
+                int seek_time = abs_diff(current_head, requests[j].track);
+                total_seek_time += seek_time;
+                current_head = requests[j].track;
+                requests[j].is_serviced = 1;
+
+                printf(" -> %d", current_head);
+                break;
+            }
+        }
+    }
+
+    printf("\nTotal Seek Time: %d\n", total_seek_time);
+    printf("Average Seek Time: %.2f\n", (float)total_seek_time / num_requests);
+}
+
+int main() {
+    int num_requests, initial_head;
+
+    printf("Enter number of disk requests: ");
+    scanf("%d", &num_requests);
+
+    DiskRequest requests[MAX_REQUESTS];
+    printf("Enter track numbers for the requests:\n");
+    for (int i = 0; i < num_requests; i++) {
+        printf("Request %d: ", i + 1);
+        scanf("%d", &requests[i].track);
+        requests[i].is_serviced = 0;
+    }
+
+    printf("Enter initial head position: ");
+    scanf("%d", &initial_head);
+
+    adaptive_disk_reordering(requests, num_requests, initial_head);
+
+    return 0;
+}