Merge pull request #213 from tanishkapall/merge-sort

Create merge_sort.c

Author: Pradeepsingh61

C/algorithms/sorting/merge_sort.c

@@ -0,0 +1,81 @@
+#include <stdio.h>
+
+// Function to merge two halves into a sorted array
+void merge(int arr[], int left, int mid, int right) {
+    int n1 = mid - left + 1;
+    int n2 = right - mid;
+
+    // Temporary arrays
+    int L[n1], R[n2];
+
+    // Copy data to temporary arrays
+    for (int i = 0; i < n1; i++)
+        L[i] = arr[left + i];
+    for (int j = 0; j < n2; j++)
+        R[j] = arr[mid + 1 + j];
+
+    // Merge the temporary arrays back into arr[left..right]
+    int 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++;
+    }
+
+    // Copy remaining elements of L[], if any
+    while (i < n1) {
+        arr[k] = L[i];
+        i++;
+        k++;
+    }
+
+    // Copy remaining elements of R[], if any
+    while (j < n2) {
+        arr[k] = R[j];
+        j++;
+        k++;
+    }
+}
+
+// Function to implement merge sort recursively
+void mergeSort(int arr[], int left, int right) {
+    if (left < right) {
+        int mid = left + (right - left) / 2;
+
+        // Sort first half
+        mergeSort(arr, left, mid);
+        // Sort second half
+        mergeSort(arr, mid + 1, right);
+
+        // Merge sorted halves
+        merge(arr, left, mid, right);
+    }
+}
+
+int main() {
+    int n;
+    printf("Enter the number of elements: ");
+    scanf("%d", &n);
+
+    int arr[n];
+    printf("Enter %d elements:\n", n);
+    for (int i = 0; i < n; i++) {
+        scanf("%d", &arr[i]);
+    }
+
+    // Call mergeSort on entire array
+    mergeSort(arr, 0, n - 1);
+
+    printf("Sorted array:\n");
+    for (int i = 0; i < n; i++) {
+        printf("%d ", arr[i]);
+    }
+    printf("\n");
+
+    return 0;
+}