使用递归的数字位数

给定一个数字，我们需要使用递归来找到其数字的总和。

例子：

Input : 12345
Output : 15

Input : 45632
Output :20
          

分步执行的过程，可以更好地了解算法的工作原理。
设数字为12345。
步骤1-> 12345％10，等于-5 +(将12345/10发送到下一步)
步骤2-> 1234％10等于-4 +(将1234/10发送到下一步)
步骤3-> 123％10等于-3 +(将123/10发送到下一步)
步骤4-> 12％10等于-2 +(发送12/10到下一步)
步骤5-> 1％10等于-1 +(将1/10发送到下一步)
步骤6-> 0算法停止
下图将说明递归的过程

C++

// Recursive C++ program to find sum of digits 
// of a number 
#include  
using namespace std; 
  
// Function to check sum of digit using recursion 
int sum_of_digit(int n) 
{ 
    if (n == 0) 
    return 0; 
    return (n % 10 + sum_of_digit(n / 10)); 
} 
  
// Driven code 
int main() 
{ 
    int num = 12345; 
    int result = sum_of_digit(num); 
    cout << "Sum of digits in "<< num 
       <<" is "<

---

C

// Recursive C program to find sum of digits 
// of a number
#include 
  
// Function to check sum of digit using recursion
int sum_of_digit(int n)
{
    if (n == 0)
       return 0;
    return (n % 10 + sum_of_digit(n / 10));
}
  
// Driven Program to check above
int main()
{
    int num = 12345;
    int result = sum_of_digit(num);
    printf("Sum of digits in %d is %d\n", num, result);
    return 0;
}

Java

// Recursive java program to 
// find sum of digits of a number
import java.io.*;
  
class sum_of_digits
{
    // Function to check sum 
    // of digit using recursion
    static int sum_of_digit(int n)
    { 
        if (n == 0)
            return 0;
        return (n % 10 + sum_of_digit(n / 10));
    }
  
    // Driven Program to check above
    public static void main(String args[])
    {
        int num = 12345;
        int result = sum_of_digit(num);
        System.out.println("Sum of digits in " + 
                           num + " is " + result);
    }
}
  
// This code is contributed by Anshika Goyal.

Python3

# Recursive Python3 program to 
# find sum of digits of a number
  
# Function to check sum of
# digit using recursion
def sum_of_digit( n ):
    if n == 0:
        return 0
    return (n % 10 + sum_of_digit(int(n / 10)))
  
# Driven code to check above
num = 12345
result = sum_of_digit(num)
print("Sum of digits in",num,"is", result)
  
# This code is contributed by "Sharad_Bhardwaj".

C#

// Recursive C# program to 
// find sum of digits of a number
using System;
  
class GFG {
      
    // Function to check sum 
    // of digit using recursion
    static int sum_of_digit(int n)
    { 
        if (n == 0)
            return 0;
              
        return (n % 10 + sum_of_digit(n / 10));
    }
  
    // Driven Program to check above
    public static void Main()
    {
        int num = 12345;
        int result = sum_of_digit(num);
        Console.WriteLine("Sum of digits in " + 
                           num + " is " + result);
    }
}
  
// This code is contributed by Anant Agarwal.

输出：

Sum of digits in 12345 is 15