void countInversions(int* A,int left,int right)
{
int mid;
if(left < right)
{
mid = (left+right)/2;
countInversions(A,left,mid);
countInversions(A,mid+1,right);
countSplit(A,left,mid,right);
}
return;
}
int main(){
int arr[] = {1, 20, 6, 4, 5};
printf("\nNumber of inversions : %d",countInversions(arr, sizeof(arr)/sizeof(arr[0])));
return 0;
}
public static int countInversions(int nums[])
{
int mid = nums.length/2, k;
int countLeft, countRight, countMerge;
if (nums.length <= 1)
return 0;
int left[] = new int[mid];
int right[] = new int[nums.length - mid];
for (k = 0; k < mid; k++)
left[k] = nums[k];
for (k = 0; k < nums.length - mid; k++)
right[k] = nums[mid+k];
countLeft = countInversions (left);
countRight = countInversions (right);
int result[] = new int[nums.length];
countMerge = mergeAndCount (left, right, result);
for (k = 0; k < nums.length; k++)
nums[k] = result[k];
return (countLeft + countRight + countMerge);
}
int main(void)
{
FILE* fp;
fp = fopen("Integerarray","r");
int counton = 100000;
int val;
int* A = (int*)malloc(counton*sizeof(int));
int i = 0;
while((fscanf(fp,"%d",&A[i])) != EOF)
{
i++;
}
countInversions(A,0,counton-1);
printf("Count = %ld\n",count);
return 0;
}
