MeargeSort.c

//merge_sort
/* Merge sort in C */
#include<stdio.h>
#include<stdlib.h>
void Merge(int *A,int *L,int leftCount,int *R,int rightCount) {
    int i,j,k;
    i = 0; j = 0; k =0;
    
    while(i<leftCount && j< rightCount) {
        if(L[i]  < R[j]) A[k++] = L[i++];
        else A[k++] = R[j++];
    }
    while(i < leftCount) A[k++] = L[i++];
    while(j < rightCount) A[k++] = R[j++];
}


void MergeSort(int *A,int n) {
    int mid,i, *L, *R;
    if(n < 2) return;
    
    mid = n/2;
    L = (int*)malloc(mid*sizeof(int));
    R = (int*)malloc((n- mid)*sizeof(int));
    
    for(i = 0;i<mid;i++) L[i] = A[i];
    for(i = mid;i<n;i++) R[i-mid] = A[i];
    MergeSort(L,mid);
    MergeSort(R,n-mid);
    Merge(A,L,mid,R,n-mid);
    free(L);
    free(R);
}

int main() {
    
    
    int A[] = {6,2,3,1,9,10,15,13,12,17};
    int i,numberOfElements;
    numberOfElements = sizeof(A)/sizeof(A[0]);//good
    MergeSort(A,numberOfElements);
    for(i = 0;i < numberOfElements;i++) printf("%d ",A[i]);
    return 0;
}