Java中的史密斯数字
一个合成数字，其数字总和等于其素因子的数字总和。
Ex: 58 = 2 x 29 (5 + 8 = 12) (2+ 2 + 9 = 12)
程序
public class SmithNumbers {
public static boolean isPrime(int number) {
int loop;
int prime = 1;
for(loop = 2; loop < number; loop++) {
if((number % loop) == 0) {
prime = 0;
}
}
if (prime == 1) {
return true;
} else {
return false;
}
}
public static ArrayList<Integer> primeFactors(int number) {
int sum = 0;
ArrayList al = new ArrayList();
for(int i = 2; i< number; i++) {
while(number % i == 0) {
System.out.println(i+" ");
al.add(i);
number = number/i;
}
}
if(number >2) {
System.out.println(number);
al.add(number);
}
return al;
}
public static void main(String args[]) {
Scanner sc = new Scanner(System.in);
System.out.println("输入数字：");
int num = sc.nextInt();
int sum = 0;
if(isPrime(num)) {
System.out.println("Given number is not smith number ");
} else {
ArrayList<Integer> arrayList = primeFactors(num);
System.out.println("Prime factors of the given number are"+arrayList);
Iterator it = arrayList.iterator();
while(it.hasNext()) {
int n = (int) it.next();
System.out.println(n);
while(n!=0) {
sum = sum+n%10;
n = n/10;
}
}
int temp = 0;
while(num != 0) {
temp = temp + num%10;
num = num/10;
}
System.out.println("sum of the digits of the numbers of the prime factorization: "+sum);
System.out.println("Sum of digits in the given number: "+temp);
if(temp==sum) {
System.out.println("Given number is a smith number");
} else {
System.out.println("Given number is not smith number ");
}
}
}
}输出结果
输入数字： 648 2 2 2 3 3 3 3 Prime factors of the given number are[2, 2, 2, 3, 3, 3, 3] 2 2 2 3 3 3 3 sum of the digits of the numbers of the prime factorization: 18 Sum of digits in the given number: 18 Given number is a smith number