[count inversion] bản hoàn chỉnh

#include<stdio.h>
#include<stdlib.h>

void print_array(int a[],int n)
{
       for ( int i = 0; i < n; i++ )
                        printf( "%d ",a[i]);
           printf( "\n");
}
int MergeandCountSplitInv(int a[], int l, int m, int r)
{
    int i,j,k;
    int *b, *c;
    b = (int*)malloc(100);
    c = (int*)malloc(100);

    int t1 = 0;
    for(i = l; i <= m; i++)
        *(b+(t1++)) = a[i];
    int t2 = 0;
    for(j = m+1; j <= r; j++)
        *(c+(t2++)) = a[j];

    i=l;
    j=m+1;
    k = l;
        int i1,j1;
        i1=0;
        j1=0;
    int inversion = 0;
    int remain_elem = 0;
    while(i1<t1&&j1<t2) {
       if(b[i1]<c[j1])
           a[k++] = b[i1++];
       else
       {
           // count remain elements of array b
           remain_elem = t1 - i1;
           inversion += remain_elem;
           a[k++] = c[j1++];
       }
    }
    while(i1<t1)
        a[k++] = b[i1++];
    while(j1<t2)
        a[k++] = c[j1++];

    free(b);
    free(c);
    print_array(a,7);
    return inversion;
}
int SortandCount(int a[], int l, int r)
{
        int m;
        int x,y,z;
        if(l>=r)
            return 0;
        else {
            m = (int)((l+r)/2);
            x = SortandCount(a,l,m);
            y = SortandCount(a,m+1,r);
            z = MergeandCountSplitInv(a,l,m,r);
        }
        return x+y+z;
}
int main(int argc, char* argv)
{
        int a[] = { 2,7,6,3,4,5,1};
                int n = sizeof(a)/sizeof(int);
        printf("%d\n",SortandCount(a,0,n-1));
        system("pause");
        return 0;
}