[英]Factorial Java Program
我想使用 for 循環在 java 中執行階乘程序。 例如,我想接受用戶輸入,比方說10
,然后乘以10*9*8*7*6*5*4*3*2*1
。 我需要幫助構建for
循環。 下面的代碼是我目前所擁有的全部代碼,因為我不確定 go 之后的位置。
import java.util.Scanner;
import java.lang.Math;
public class factorial {
public static void main(String[] args) {
int num;
Scanner input = new Scanner(System.in);
System.out.println("Enter a number: ");
num = input.nextInt();
}
}
import java.util.Scanner;
public class Main {
public static void main(String[] args)
{
System.out.print("Enter a number: ");
Scanner input = new Scanner(System.in);
int num = input.nextInt();
long factorialResult = factorialRecursive(num);
System.out.println(factorialResult);
}
public static long factorialRecursive(int n) {
if (n == 0 || n == 1 )
return 1;
return n * factorialRecursive(n - 1);
}
}
來源: learn.uncox.com
如果數量很大,就會發生“stackoverflow”。
嘗試
public static void main(String[] args) {
int num;
int fact=1;
Scanner input = new Scanner(System.in);
System.out.println("Enter a number: ");
num = input.nextInt();
for (int i=2;i<=num; i++){
fact=fact*i;
}
System.out.println("Factorial: "+fact);
}
正如@Marko Topolnik 在評論中提到的,此代碼適用於最多 12 的輸入。對於更大的輸入,由於溢出將輸出無窮大。
對於大於 12 的數字,您應該使用更高的數據類型,例如BigInteger
你可以試試:
public static void main(String[] args) {
BigInteger num;
BigInteger fact = BigInteger.valueOf(1);
Scanner input = new Scanner(System.in);
System.out.println("Enter a number: ");
num = input.nextBigInteger();
for (int i = 2; i <= num; i++){
fact = fact.multiply(BigInteger.valueOf(i));
}
System.out.println(fact);
}
為什么要費心計算呢?
public int factorial ( int n ) {
switch(n){
case 0: return 1;
case 1: return 1;
case 2: return 2;
case 3: return 6;
case 4: return 24;
case 5: return 120;
case 6: return 720;
case 7: return 5040;
case 8: return 40320;
case 9: return 362880;
case 10: return 3628800;
case 11: return 39916800;
case 12: return 479001600;
default : throw new IllegalArgumentException();
}
資料來源: @埃默里
這是我的程序
class FactorialUsingFor
{
public static void main(String arg[])
{
int factorial = 1;
int number = 6;
for(int i = 1; i <= number; i++)
{
factorial *= i;
}
System.out.println("Factorial of number " + number + " is " + factorial);
}
}
int sum = 1;
for (int i = 2;i <= num;i++) {
sum = sum * i;
}
試試這個程序:=
import java.util.*;
public class Factorials {
public static void main(String[] args){
Scanner sc=new Scanner(System.in);
int i,num,a,b;
int c=1;
System.out.println("Enter the no.= ");
num=sc.nextInt();
for(i=1;i<=num;i++){
c=i*c;
}
System.out.println("Factorial is "+c);
}
}
import java.util.Scanner;
public class Factorial {
public static void main(String[] args){
Scanner scn = new Scanner(System.in);
System.out.println("Enter the number to find factorial");
int o=scn.nextInt();
int count=0,b=o-1,res=(o*(o-1)),r=0;
while(count!=1)
{
count=b-1;
r=count*res;
res=r;
r=1;
b=b-1;
}
System.out.println(res);
}
}
int factorialLoop(int val) {
int result = 1 ;
for (int i = val ; i>= 1 ; i--){
result = result * i ;
}
return result ;
}
int factorielRecursive(int val){
if(1 <= val){
return val*factorialRecursive(val-1);
}else {
return 1;
}
}
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