#include <stdio.h>
#include <stdlib.h>
#include <time.h>
// Function to merge two subarrays
void merge(int arr[], int left, int mid, int right) {
int i, j, k;
int n1 = mid - left + 1;
int n2 = right - mid;
int L[n1], R[n2];
for (i = 0; i < n1; i++)
L[i] = arr[left + i];
for (j = 0; j < n2; j++)
R[j] = arr[mid + 1 + j];
i = 0;
j = 0;
k = left;
while (i < n1 && j < n2) {
if (L[i] <= R[j]) {
arr[k] = L[i];
i++;
} else {
arr[k] = R[j];
j++;
}
k++;
}
while (i < n1) {
arr[k] = L[i];
i++;
k++;
}
while (j < n2) {
arr[k] = R[j];
j++;
k++;
}
}
// Merge Sort function
void mergeSort(int arr[], int left, int right) {
if (left < right) {
int mid = left + (right - left) / 2;
mergeSort(arr, left, mid);
mergeSort(arr, mid + 1, right);
merge(arr, left, mid, right);
}
}
int main() {
int n;
printf("Enter number of elements (n > 5000): ");
scanf("%d", &n);
if (n <= 5000) {
printf("Please enter n greater than 5000.\n");
return 1;
}
int *arr = (int *)malloc(n * sizeof(int));
if (arr == NULL) {
printf("Memory allocation failed.\n");
return 1;
}
// Generating random numbers
srand(time(0));
for (int i = 0; i < n; i++) {
arr[i] = rand() % 100000; // Random numbers between 0 and 99999
}
clock_t start, end;
double cpu_time_used;
start = clock();
mergeSort(arr, 0, n - 1);
end = clock();
cpu_time_used = ((double)(end - start)) / CLOCKS_PER_SEC;
printf("Time taken to sort %d elements: %f seconds\n", n, cpu_time_used);
free(arr);
return 0;
}
