Java程序查找数字的唯一素数的乘积
给定一个数 n,我们需要找到它所有唯一素因子的乘积。质因数:它基本上是质数本身的一个数的因数。
例子:
Input: num = 10
Output: Product is 10
Explanation:
Here, the input number is 10 having only 2 prime factors and they are 5 and 2.
And hence their product is 10.
Input : num = 25
Output: Product is 5
Explanation:
Here, for the input to be 25 we have only one unique prime factor i.e 5.
And hence the required product is 5.
方法1(简单)
使用从 i = 2 到 n 的循环并检查 i 是否是 n 的因数,然后检查 i 是否是素数本身,如果是,则将产品存储在产品变量中并继续此过程直到 i = n。
// Java program to find product of
// unique prime factors of a number.
public class GFG {
public static long productPrimeFactors(int n)
{
long product = 1;
for (int i = 2; i <= n; i++) {
// Checking if 'i' is factor of num
if (n % i == 0) {
// Checking if 'i' is a Prime number
boolean isPrime = true;
for (int j = 2; j <= i / 2; j++) {
if (i % j == 0) {
isPrime = false;
break;
}
}
// condition if 'i' is Prime number
// as well as factor of num
if (isPrime) {
product = product * i;
}
}
}
return product;
}
public static void main(String[] args)
{
int n = 44;
System.out.print(productPrimeFactors(n));
}
}
// Contributed by _omg
输出:
22
方法二(高效)
这个想法是基于高效程序来打印给定数字的所有素因子
// Java program to find product of
// unique prime factors of a number.
import java.util.*;
import java.lang.*;
public class GFG {
public static long productPrimeFactors(int n)
{
long product = 1;
// Handle prime factor 2 explicitly so that
// can optimally handle other prime factors.
if (n % 2 == 0) {
product *= 2;
while (n % 2 == 0)
n = n / 2;
}
// n must be odd at this point. So we can
// skip one element (Note i = i +2)
for (int i = 3; i <= Math.sqrt(n); i = i + 2) {
// While i divides n, print i and
// divide n
if (n % i == 0) {
product = product * i;
while (n % i == 0)
n = n / i;
}
}
// This condition is to handle the case when n
// is a prime number greater than 2
if (n > 2)
product = product * n;
return product;
}
public static void main(String[] args)
{
int n = 44;
System.out.print(productPrimeFactors(n));
}
}
// Contributed by _omg
输出:
22
更多详细信息,请参阅关于一个数的唯一素因数乘积的完整文章!