1 second
256 megabytes
standard input
standard output
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.
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.
Print a single integer — the number of rooms where George and Alex can move in.
3 1 1 2 2 3 3
0
3 1 10 0 10 10 10
2
sb题
判断qi-2>=pi的有多少个
#include<iostream>
#include<cstring>
#include<cstdio>
using namespace std;
int n,m;
int main()
{
scanf("%d",&n);
int x,y;
for(int i=1;i<=n;i++)
{
scanf("%d%d",&x,&y);
if(y-x>=2)m++;
}
printf("%d",m);
return 0;
}