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 题意：有n个寝室，一共可以住qi,已经住了pi个，问再来两个可以住进去几个寝室 思路：直接计算的大水题#include <iostream> #include <cstdio> #include <cstring> #include <algorithm> using namespace std; int main() { int n; scanf("%d", &n); int p, q, ans = 0; for (int i = 0; i < n; i++) { scanf("%d%d", &q, &p); if (p - q >= 2) ans++; } printf("%d\n", ans); return 0; }
Codeforces Round #267 (Div. 2) A. George and Accommodation
原文：http://blog.csdn.net/u011345136/article/details/39393629