代码：

//2_9.cpp
//读入一系列整数，统计出正整数个数i和负整数个数j,读入0则结束
#include <iostream>
using namespace std;
int main() {
	int i = 0, j = 0, n;
	cout << "Please enter some integers(enter 0 to quit):" << endl;
	cin >> n;
	while (n != 0) {
		if (n > 0) i++;
		if (n < 0)j++;
		cin >> n;
	}
	cout << "Count of positive integers :" << i << endl;
	cout << "Count of negetive integers :" << j << endl;

	return 0;
}

运行结果：