NYOJ-169 primes

Prime Number
Time limit: Ms | Memory Limit: 65535 KB
Difficulty: 1
Describe
Entering the Expo Park, an information and communication museum, visitors will receive an unprecedented experience of the most sophisticated interactive, a full of creative and joyful information and communication interactive experience show will be presented in a new form, from the audience step into the pavilion from the first step, will be inseparable from the handheld terminal, the future of human dreams from the visitor's pocket unfold.

In the dream garden of the waiting area, visitors begin their magical journey of experience, with the use of terminals such as mobile phones to participate in interactive games with the virtual character KR in the Dream Theatre. Kong for guessing games. When the screen appears with an integer x, if you can compare the KR. The Kong faster sends out the nearest prime number answer, and you will get an unexpected gift.

For example: When the screen appears 22 o'clock, your answer should be 23; When the screen appears 8 o'clock, your answer should be 7; if x itself is a prime number, answer X; If the number of primes closest to X is two, the number is greater than its prime.

Input
First line: N the number of integers to guess
Next there are n rows with a positive integer x per line
1<=n<=5 1<=x<=1000
Output
The output has n rows, and each row is the nearest prime number corresponding to X
Sample input
4
22
5
18
8
Sample output
23
5
19
7
Source
The third Henan Province Program design Competition

The main topic: to find the number of the nearest prime, specific requirements see the topic.

My side. The use of the number of primes is the method of determining the number of twins, see: http://blog.csdn.net/code_pang/article/details/7880245

#include <iostream>#include <cstdio>using namespace STD;BOOLIsPrime (intNUM) {if(num==1)return false;if(num==2|| num==3)return true;if(num%6!=1&& num%6!=5)return false; for(intI=5; i*i<=num;i+=6)if(num%i==0|| num% (i+2)==0)return false;return true;}intMain () {intTscanf("%d", &t); while(t--) {intNscanf("%d", &n);if(IsPrime (n)) {cout<<n<<endl;Continue; }intAnt=0; for(intj=1;j< -; j + +) {if(IsPrime (N+J)) {if(IsPrime (N-J)) {cout<<n+j<<endl; Ant=1; }Else{cout<<n+j<<endl; Ant=1; }            }Else if(IsPrime (N-J)) {cout<<n-j<<endl; Ant=1; }if(ant==1) Break; }    }return 0;}

Only on behalf of personal views, welcome to Exchange discussion, do not spray ~ ~

Photoby:wlop

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NYOJ-169 primes