Add implementation of merge sort in C

Sorting/lcs1.c

@@ -0,0 +1,79 @@
+
+#include<stdio.h>
+#include<string.h>
+#include<stdlib.h>
+int max(int a, int b)
+{
+	 return (a > b)? a : b; 
+} 
+
+/* Returns length of LCS for X[0..m-1], Y[0..n-1] */
+void lcs( char *X, char *Y, int m, int n ) 
+{ 
+   int L[m+1][n+1]; 
+
+   /* Following steps build L[m+1][n+1] in bottom up fashion. Note 
+      that L[i][j] contains length of LCS of X[0..i-1] and Y[0..j-1] */
+   for (int i=0; i<=m; i++) 
+   { 
+     for (int j=0; j<=n; j++) 
+     { 
+       if (i == 0 || j == 0) 
+         L[i][j] = 0; 
+       else if (X[i-1] == Y[j-1]) 
+         L[i][j] = L[i-1][j-1] + 1; 
+       else
+         L[i][j] = max(L[i-1][j], L[i][j-1]); 
+     } 
+   } 
+
+   // Following code is used to print LCS 
+   int index = L[m][n]; 
+
+   // Create a character array to store the lcs string 
+   char lcs[index+1]; 
+   lcs[index] = '\0'; // Set the terminating character 
+
+   // Start from the right-most-bottom-most corner and 
+   // one by one store characters in lcs[] 
+   int i = m, j = n; 
+   while (i > 0 && j > 0) 
+   { 
+      // If current character in X[] and Y are same, then 
+      // current character is part of LCS 
+      if (X[i-1] == Y[j-1]) 
+      { 
+          lcs[index-1] = X[i-1]; // Put current character in result 
+          i--; j--; index--;     // reduce values of i, j and index 
+      } 
+
+      // If not same, then find the larger of two and 
+      // go in the direction of larger value 
+      else if (L[i-1][j] > L[i][j-1]) 
+         i--; 
+      else
+         j--; 
+   } 
+
+   // Print the lcs 
+   printf("LCS is %s", lcs);
+}   
+
+/* Driver program to test above function */
+int main() 
+{ 
+  int x, y, i;
+  printf("Enter the sizes of character arrays");
+  scanf("%d%d", &x, &y);
+  char X[x], Y[y];
+  printf("Enter the elements of 1st array");
+  for(i = 0; i < x; i++)
+	scanf("%c", &X[i]);
+  printf("Enter the elements of 2nd array");
+  for(i = 0; i < y; i++)
+	scanf("%c", &Y[i]);
+  int m = strlen(X); 
+  int n = strlen(Y); 
+  lcs(X, Y, m, n); 
+  return 0; 
+} 

Sorting/merge.c

@@ -0,0 +1,109 @@
+
+#include<stdlib.h> 
+#include<stdio.h> 
+
+// Merges two subarrays of arr[]. 
+// First subarray is arr[l..m] 
+// Second subarray is arr[m+1..r] 
+void merge(int arr[], int l, int m, int r) 
+{ 
+    int i, j, k; 
+    int n1 = m - l + 1; 
+    int n2 =  r - m; 
+
+    /* create temp arrays */
+    int L[n1], R[n2]; 
+
+    /* Copy data to temp arrays L[] and R[] */
+    for (i = 0; i < n1; i++) 
+        L[i] = arr[l + i]; 
+    for (j = 0; j < n2; j++) 
+        R[j] = arr[m + 1+ j]; 
+
+    /* Merge the temp arrays back into arr[l..r]*/
+    i = 0; // Initial index of first subarray 
+    j = 0; // Initial index of second subarray 
+    k = l; // Initial index of merged subarray 
+    while (i < n1 && j < n2) 
+    { 
+        if (L[i] <= R[j]) 
+        { 
+            arr[k] = L[i]; 
+            i++; 
+        } 
+        else
+        { 
+            arr[k] = R[j]; 
+            j++; 
+        } 
+        k++; 
+    } 
+
+    /* Copy the remaining elements of L[], if there 
+       are any */
+    while (i < n1) 
+    { 
+        arr[k] = L[i]; 
+        i++; 
+        k++; 
+    } 
+
+    /* Copy the remaining elements of R[], if there 
+       are any */
+    while (j < n2) 
+    { 
+        arr[k] = R[j]; 
+        j++; 
+        k++; 
+    } 
+} 
+
+/* l is for left index and r is right index of the 
+   sub-array of arr to be sorted */
+void mergeSort(int arr[], int l, int r) 
+{ 
+    if (l < r) 
+    { 
+        // Same as (l+r)/2, but avoids overflow for 
+        // large l and h 
+        int m = l+(r-l)/2; 
+
+        // Sort first and second halves 
+        mergeSort(arr, l, m); 
+        mergeSort(arr, m+1, r); 
+
+        merge(arr, l, m, r); 
+    } 
+} 
+
+/* UTILITY FUNCTIONS */
+/* Function to print an array */
+void printArray(int A[], int size) 
+{ 
+    int i; 
+    for (i=0; i < size; i++) 
+        printf("%d ", A[i]); 
+    printf("\n"); 
+} 
+
+/* Driver program to test above functions */
+int main() 
+{ 
+
+    int k, i;
+    printf("Enter the no of inputs\n");
+    scanf("%d", &k);
+    int arr[k];
+    for(i = 0; i < k; i++)
+          scanf("%d", &arr[i]); 
+    int arr_size = sizeof(arr)/sizeof(arr[0]); 
+
+    printf("Given array is \n"); 
+    printArray(arr, arr_size); 
+
+    mergeSort(arr, 0, arr_size - 1); 
+
+    printf("\nSorted array is \n"); 
+    printArray(arr, arr_size); 
+    return 0; 
+}