A – FYI

发布于 2020-10-08  333 次阅读




FYI

In the United States of America, telephone numbers within an area code consist of 7 digits: the prefix number is the first 3 digits and the line number is the last 4 digits. Traditionally, the 555 prefix number has been used to provide directory information and assistance as in the following examples:

555-1212

555-9876

555-5000

555-7777

Telephone company switching hardware would detect the 555 prefix and route the call to a directory information operator. Now-a-days, telephone switching is done digitally and somewhere along the line a computer decides where to route calls.

For this problem, write a program that determines if a supplied 7-digit telephone number should be routed to the directory information operator, that is, the prefix number is 555.

Input
The input consists of a single line containing a 7-digit positive integer N, (1000000 <= N <= 9999999).

Output
The single output line consists of the word YES if the number should be routed to the directory information operator or NO if the number should not be routed to the directory information operator.

Sample Input
5551212

Sample Output
YES

Sample Input 2
5519876

Sample Output 2
NO

Sample Input 3
5055555

Sample Output 3
NO

题意:水题。只需要将存入字符串判断前三个字符是否为‘5’即可AC本题。
思路:依照题意模拟。

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main() {
	string s;
	cin>>s;
	int flag=0;
	for(int i=0;i<3;i++)
	{
		if(s[i]!='5')
		{
			flag=1;
			break;
		}
	} 
	if(flag)
		cout<<"NO"<<endl;
	else
		cout<<"YES"<<endl;
	return 0;
}