int merge(int *A, int left, int mid, int right){    int *temp = new int[right-left+1];    int num = 0;    int i = left;    int j = mid+1;    int index = 0;    while(i<=mid && j<=right){        if(A[i]>A[j]){            num+=mid-i+1;            temp[index]=A[j];            j++;        }        else{            temp[index]=A[i];            i++;        }        index++;    }    if(i<=mid)        for(;i<=mid;i++){            temp[index]=A[i];            index++;        }    if(j<=right)        for(;j<=right;j++){            temp[index]=A[j];            index++;        }    for(int k=0; k<index; k++)        A[left+k]=temp[k];        delete []temp;    return num;}int inversion(int *A, int left, int right){    if(left>=right)  return 0;    int mid=(left+right)/2;    int num1=inversion(A,left,mid);    int num2=inversion(A, mid+1, right);    return num1+num2+merge(A,left,mid,right);}int main(){    int A[5]={9,8,7,6,5};    cout << inversion(A,0,4);    return 0;}