检查一个数字是否为幻数(数字的递归和为 1)
原文:https://www . geesforgeks . org/check-number-magic-recursive-sum-digits-1/
如果一个数的位数总和是通过每次相加后的位数总和递归计算出来的，那么这个数被称为幻数。如果一位数是 1，那么这个数字就是一个神奇的数字。
例如- 号= 50113 =>5+0+1+1+3 = 10 =>1+0 = 1 这是一个幻数
例如- 号= 1234 =>1+2+3+4 = 10 =>1+0 = 1 这是一个幻数
示例:
Input : 1234
Output : Magic Number
Input : 12345
Output : Not a magic Number
这种方法使用暴力。该函数不断增加数字，直到达到一位数的总和。为了理解我如何计算一位数的总和，请查看本页- 查找一个数字的位数总和，直到总和变成一位数
C++
// CPP program to check if a number is Magic
// number.
#include<iostream>
using namespace std;
bool isMagic(int n)
{
int sum = 0;
// Note that the loop continues
// if n is 0 and sum is non-zero.
// It stops when n becomes 0 and
// sum becomes single digit.
while (n > 0 || sum > 9)
{
if (n == 0)
{
n = sum;
sum = 0;
}
sum += n % 10;
n /= 10;
}
// Return true if sum becomes 1.
return (sum == 1);
}
// Driver code
int main()
{
int n = 1234;
if (isMagic(n))
cout << "Magic Number";
else
cout << "Not a magic Number";
return 0;
}
Java 语言(一种计算机语言，尤用于创建网站)
// Java program to check if
// a number is Magic number.
class GFG
{
public static boolean isMagic(int n)
{
int sum = 0;
// Note that the loop continues
// if n is 0 and sum is non-zero.
// It stops when n becomes 0 and
// sum becomes single digit.
while (n > 0 || sum > 9)
{
if (n == 0)
{
n = sum;
sum = 0;
}
sum += n % 10;
n /= 10;
}
// Return true if sum becomes 1.
return (sum == 1);
}
// Driver code
public static void main(String args[])
{
int n = 1234;
if (isMagic(n))
System.out.println("Magic Number");
else
System.out.println("Not a magic Number");
}
}
// This code is contributed by Anshika Goyal.
Python 3
# Python3 program to check
# if a number is Magic
# number.
def isMagic(n):
sum = 0;
# Note that the loop
# continues if n is 0
# and sum is non-zero.
# It stops when n becomes
# 0 and sum becomes single
# digit.
while (n > 0 or sum > 9):
if (n == 0):
n = sum;
sum = 0;
sum = sum + n % 10;
n = int(n / 10);
# Return true if
# sum becomes 1.
return True if (sum == 1) else False;
# Driver code
n = 1234;
if (isMagic(n)):
print("Magic Number");
else:
print("Not a magic Number");
# This code is contributed
# by mits.
C
// C# program to check if
// a number is Magic number.
using System;
class GFG
{
public static bool isMagic(int n)
{
int sum = 0;
// Note that the loop continues
// if n is 0 and sum is non-zero.
// It stops when n becomes 0 and
// sum becomes single digit.
while (n > 0 || sum > 9)
{
if (n == 0)
{
n = sum;
sum = 0;
}
sum += n % 10;
n /= 10;
}
// Return true if sum becomes 1.
return (sum == 1);
}
// Driver code
public static void Main()
{
int n = 1234;
if (isMagic(n))
Console.WriteLine("Magic Number");
else
Console.WriteLine("Not a magic Number");
}
}
// This code is contributed by vt_m.
服务器端编程语言（Professional Hypertext Preprocessor 的缩写）
<?php
// PHP program to check if
// a number is Magic number.
function isMagic($n)
{
$sum = 0;
// Note that the loop
// continues if n is 0
// and sum is non-zero.
// It stops when n becomes
// 0 and sum becomes single
// digit.
while ($n > 0 || $sum > 9)
{
if ($n == 0)
{
$n = $sum;
$sum = 0;
}
$sum += $n % 10;
$n /= 10;
}
// Return true if
// sum becomes 1.
return ($sum == 1);
}
// Driver code
$n = 1234;
if (isMagic($n))
echo"Magic Number";
else
echo "Not a magic Number";
// This code is contributed
// by nitin mittal.
?>
java 描述语言
<script>
// JavaScript program to check if
// a number is Magic number.
function isMagic( n)
{
var sum = 0;
// Note that the loop continues
// if n is 0 and sum is non-zero.
// It stops when n becomes 0 and
// sum becomes single digit.
while (n > 0 || sum > 9)
{
if (n = 0)
{
n = sum;
sum = 0;
}
sum += n % 10;
n /= 10;
}
// Return true if sum becomes 1.
return (sum = 1);
}
// Driver code
var n = 1234;
if (isMagic(n))
document.write("Magic Number");
else
document.write("Not a magic Number");
// This code is contributed by shivanisinghss2110
</script>
Output:
Magic Number
高效进场(捷径):还有一个验证幻数的捷径方法。该函数将确定输入除以 9 的余数是否为 1。如果是 1，那么这个数就是一个幻数。9 的可除性规则说，如果一个数的总和也能被 9 整除，那么这个数就能被 9 整除。因此，如果一个数能被 9 整除，那么，递归地，所有的数字和也能被 9 整除。最后的数字总和总是 9。原数增加 1 会使最终值增加 1，使其为 10，最终和为 1，从而验证其为幻数。
C++
// C++ program to check
// Whether the number is Magic or not.
#include <iostream>
using namespace std;
int main() {
// Accepting sample input
int x = 1234;
// Condition to check Magic number
if(x%9==1)
cout << ("Magic Number");
else
cout << ("Not a Magic Number");
return 0;
}
C
// C program to check
// Whether the number is Magic or not.
#include <stdio.h>
int main() {
// Accepting sample input
int x = 1234;
// Condition to check Magic number
if(x%9==1)
printf("Magic Number");
else
printf("Not a Magic Number");
return 0;
}
Java 语言(一种计算机语言，尤用于创建网站)
// Java program to check
// Whether the number is Magic or not.
class GFG{
public static void main(String[] args)
{
// Accepting sample input
int x = 1234;
// Condition to check Magic number
if (x % 9 == 1)
System.out.printf("Magic Number");
else
System.out.printf("Not a Magic Number");
}
}
// This code is contributed by Amit Katiyar
Python 3
# Python3 program to check
# Whether the number is Magic or not.
# Accepting sample input
x = 1234
# Condition to check Magic number
if (x % 9 == 1):
print("Magic Number")
else:
print("Not a Magic Number")
# This code is contributed by kirti
C
// C# program to check
// Whether the number is Magic or not.
using System;
using System.Collections.Generic;
class GFG{
public static void Main(String[] args)
{
// Accepting sample input
int x = 1234;
// Condition to check Magic number
if (x % 9 == 1)
Console.Write("Magic Number");
else
Console.Write("Not a Magic Number");
}
}
// This code is contributed by Princi Singh
java 描述语言
<script>
// JavaScript program to check
// Whether the number is Magic or not.
// Accepting sample input
var x = 1234;
// Condition to check Magic number
if (x % 9 == 1)
document.write("Magic Number");
else
document.write("Not a Magic Number");
// This code is contributed by shivanisinghss2110
</script>
Output:
Magic Number
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