CF 842A - Kirill And The Game

A. Kirill And The Game
time limit per test
2 seconds
memory limit per test
256 megabytes
input
standard input
output
standard output

Kirill plays a new computer game. He came to the potion store where he can buy any potion. Each potion 
is characterized by two integers — amount of experience and cost. The efficiency of a potion is the ratio
 of the amount of experience to the cost. Efficiency may be a non-integer number.

For each two integer numbers a and b such that l ≤ a ≤ r and x ≤ b ≤ y there is a potion with experience a
 and cost b in the store (that is, there are (r - l + 1)·(y - x + 1) potions).

Kirill wants to buy a potion which has efficiency k. Will he be able to do this?
Input

First string contains five integer numbers l, r, x, y, k (1 ≤ l ≤ r ≤ 107, 1 ≤ x ≤ y ≤ 107, 1 ≤ k ≤ 107).
Output

Print "YES" without quotes if a potion with efficiency exactly k can be bought in the store and "NO" without 
quotes otherwise.

You can output each of the letters in any register.
Examples
Input

1 10 1 10 1

Output

YES

Input

1 5 6 10 1

Output

NO

思路：

将x至y的每一个数都乘以k只要有一个数>=l并且<=r，就可以YES，如果没有，就NO。

代码：

#include <cstdio>
#include <iostream>

using namespace std;

int main()
{
	long long l,r,x,y,k;
	cin>>l>>r>>x>>y>>k;
	for(long long i=x ; i<=y ; i++)
	{
		long long mid = i*k;
		if(mid>=l && mid<=r)
		{
			cout<<"YES";
			return 0;
		}
	}
	cout<<"NO";
	return 0;
}