逆序對

#include <iostream>
#include <algorithm>
using namespace std;
void show(int * a, int b){
	for(int i = 0; i < b; i++){
		cout << a[i] << " ";
	}
	cout << endl;
}
int merge(int * a, int b, int m, int e){
	cout << "b " << b << " " << m << " " << e << endl;
	int i = b, j = m, k = 0;
	int h = 0;
	int * c = (int *)malloc(sizeof(int) * (e - b));
	while(i < m && j < e){
		if(a[i] > a[j]){
			h = h + m - i;
			c[k++] = a[j++];
		}
		else if(a[i] < a[j]){
			c[k++] = a[i++];
		}
	}
	while(i < m){
		c[k++] = a[i++];
	}
	while(j < e){
		c[k++] = a[j++];
	}
	for(i = b, k = 0; i < e; i++, k++){
		a[i] = c[k];
	}
	show(a, 8);
	return h;
}
int f(int * a,  int s, int e){
	cout << s << " " << e << endl;
	if(e - s == 1){
		return 0;
	}
	int m = (e + s) / 2;
	int t1 = f(a, s, m);
	int t2 = f(a, m, e);
	int t3 = merge(a, s, m, e);
	return t1 + t2 + t3;
}
int b[5] = {-1};
int main(){

	int a[] = {1, 2, 3, 4, 5, 6, 7, 0};
	cout << f(a, 0, 8);
}