SGU 113
113. Nearly prime numbers
time limit per test: 0.25 sec.
memory limit per test: 4096
KB
Nearly prime number is an integer positive number for which it is possible to find such primes P1 and P2 that given number is equal to P1*P2. There is given a sequence on N integer positive numbers, you are to write a program that prints “Yes” if given number is nearly prime and “No” otherwise.
Input
Input file consists of N+1 numbers. First is positive integer N (1£N£10). Next N numbers followed by N. Each number is not greater than 109. All numbers separated by whitespace(s).
Output
Write a line in output file for each number of given sequence. Write “Yes” in it if given number is nearly prime and “No” in other case.
Sample Input
1
1 #include <iostream> 2 #include <cstdio> 3 #include <cstring> 4 #include <cmath> 5 using namespace std; 6 7 int n; 8 9 bool judge(int x) { 10 int sum = 0; 11 int t; 12 for(int i = 2; i * i <= x; i++) { 13 if(x % i == 0 ) { 14 sum++; 15 t = i; 16 17 } 18 } 19 20 return sum == 1 && ((x / t == t) || x / t % t != 0) ; 21 } 22 int main() 23 { 24 25 scanf("%d",&n); 26 27 for(int i = 1; i <= n; i++) { 28 int ch; 29 scanf("%d",&ch); 30 if(judge(ch)) printf("Yes\n"); 31 else printf("No\n"); 32 } 33 return 0; 34 }
6
Sample Output
Yes
易知,我们要寻找的数除1 与自身外其他的因子数必然不超过2,假设有两个因子,则其中一个因子必然不能整除另一个因子。