第二题

George and Accommodation

Time limit 1000 ms
Memory limit 262144 kB

Problem Description

George has recently entered the BSUCP (Berland State University for Cool Programmers). George has a friend Alex who has also entered the university. Now they are moving into a dormitory.
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.

Input

The first line contains a single integer n (1 ≤ n ≤ 100) — the number of rooms.
The i-th of the next n lines contains two integers pi and qi (0 ≤ pi ≤ qi ≤ 100) — the number of people who already live in the i-th room and the room’s capacity.

#Output

Print a single integer — the number of rooms where George and Alex can move in.

Sample Input

3
1 10
0 10
10 10

##Sample Output

2

第二题

问题链接：https://vjudge.net/problem/CodeForces-467A

问题简述：

有n间房间，一间房间已有p（i）人，总共能容纳q（i）人，问能满足两人同住一间房的有几间房间

问题分析：

首先输入n确定房数，通过循环输入n次p（i）和q（i），利用逻辑表达式p（i） <= q（i） - 2确定此房是否满足并记录，最后输入记录数即可

程序说明：

用sanf输入n，通过for循环输入p（i）和q（i），并通过sum的自增来记录合适房间数，最后输出sum即可

AC通过的C语言程序如下：

#include <iostream>

int main()
{
	int n, pi, qi;
	int sum=0;
	scanf("%d", &n);
	for (int i = 0;i < n;i++)
	{
		scanf("%d%d", &pi, &qi);
		if (pi <= qi - 2)
		{
			sum++;
		}
	}
	printf("%d\n", sum);
	return 0;

    
}