这有一个,你参考一下: import java.util.ArrayList;public class PrimeNumber{ public static ArrayList getPrimeNumber(int n){ ArrayList al = new ArrayList(); for(int i = 2; i < n; i++) { boolean isPrimeNumber = true; for(int j = 2; j < i; j++) { if(i % j == 0){ isPrimeNumber = false; } } if(isPrimeNumber){ al.add(new Integer(i)); } } return al; }
public static void main(String[] args) { ArrayList al = getPrimeNumber(1000); for(int i = 0; i < al.size(); i++){ System.out.println(al.get(i)); } } }
mport java.text.DecimalFormat; import java.text.NumberFormat;public class PerfectNumber { public static void num(int n) {
int sum =0; for ( int i = 1; i <= n;i++) { sum =0; for ( int j = 1;j < i; j++) { if(i%j==0) { sum = sum + j; } } if(sum==i) { System.out.println("perfect number:"+sum); } } }
public static void main(String args[]) { num(10000); } }
import java.util.ArrayList;public class PerfectNumber{ public static ArrayList getPerfectNum(int n){ ArrayList al = new ArrayList(); int sum =0; for ( int i = 1; i <= n;i++){ sum =0; for ( int j = 1;j < i; j++) { if(i%j==0){ sum = sum + j; } } if(sum==i){ al.add(new Integer(sum)); } } return al; }
public static void main(String args[]){ ArrayList al = getPerfectNum(10000); for(int i = 0; i < al.size(); i++){ System.out.println("perfect number:" + al.get(i)); } } }
import java.applet.Applet; import java.awt.*; public class wanshu extends Applet { public void paint(Graphics g) { int b=0; g.drawString("1000以内的完全数是:",20,30); for(int i=2;i<=1000;i++) { int sum = 0; for(int j = 1 ;j<=i/2;j++) { if(i%j==0) sum = sum + j; } if(sum == i ){ g.drawString(i+"",40+b*50,60); b++;} } } }
循环一下,是否整除,用个arraylist存一下所有因子,求和判断,输出
你等着,我去写出来。
import java.util.ArrayList;public class PrimeNumber{
public static ArrayList getPrimeNumber(int n){
ArrayList al = new ArrayList();
for(int i = 2; i < n; i++)
{
boolean isPrimeNumber = true;
for(int j = 2; j < i; j++)
{
if(i % j == 0){
isPrimeNumber = false;
}
}
if(isPrimeNumber){
al.add(new Integer(i));
}
}
return al;
}
public static void main(String[] args)
{
ArrayList al = getPrimeNumber(1000);
for(int i = 0; i < al.size(); i++){
System.out.println(al.get(i));
}
}
}
import java.text.NumberFormat;public class PerfectNumber
{
public static void num(int n)
{
int sum =0;
for ( int i = 1; i <= n;i++)
{
sum =0;
for ( int j = 1;j < i; j++)
{
if(i%j==0)
{
sum = sum + j;
}
}
if(sum==i)
{
System.out.println("perfect number:"+sum);
}
}
}
public static void main(String args[])
{
num(10000);
}
}
public static ArrayList getPerfectNum(int n){
ArrayList al = new ArrayList();
int sum =0;
for ( int i = 1; i <= n;i++){
sum =0;
for ( int j = 1;j < i; j++) {
if(i%j==0){
sum = sum + j;
}
}
if(sum==i){
al.add(new Integer(sum));
}
}
return al;
}
public static void main(String args[]){
ArrayList al = getPerfectNum(10000);
for(int i = 0; i < al.size(); i++){
System.out.println("perfect number:" + al.get(i));
}
}
}
import java.awt.*;
public class wanshu extends Applet
{
public void paint(Graphics g)
{
int b=0;
g.drawString("1000以内的完全数是:",20,30);
for(int i=2;i<=1000;i++)
{
int sum = 0;
for(int j = 1 ;j<=i/2;j++)
{
if(i%j==0)
sum = sum + j;
}
if(sum == i ){
g.drawString(i+"",40+b*50,60);
b++;}
}
}
}