java記——迴圈 求一個數的所有質因數

問題及代碼：

問題描述：

輸入一個數，計算並輸出這個數所有的質因數。例如 輸入120，輸出2 2 2 3 5

程式碼：

public class Exercise4_16 {  // Main method  public static void main(String args[]) {    java.util.Scanner input = new java.util.Scanner(System.in);    // Prompt the user to enter a positive integer    System.out.print(      "Enter a positive integer: ");    int number = input.nextInt();    // Find all the smallest factors of the integer    System.out.println("The factors for " + number + " is");    int factor = 2;    while (factor <= number) {      if (number % factor == 0) {        number = number / factor;        System.out.println(factor);      }      else {        factor++;      }    }  }}

運行結果：