ACM训练题第二题

题目描述：

George and Alex want to live in the same room. The dormitory has n rooms in total. At the moment the i-th room has pi people living in it and the room can accommodate qi people in total (pi ≤ qi). Your task is to count how many rooms has free place for both George and Alex.

题解：
只要判断qi-pi的值是否大于等于2就行了

#include<iostream>
using namespace std;
int main()
{      //第二题
	int n,k=0,pi,qi;
	cin >> n;
	
	for (int i = 0; i < n; i++)
	{
		cin >> pi >> qi;
		if (qi - pi >= 2)
		{
		}
			k++;
	}
	cout << k;
	return 0;
}