一个数字可以用其数字的总和替换直到仅包含一位数字的次数

计算一个数字可以用其数字的总和替换的次数，直到它仅包含一个数字并且数字可能非常大。
例子：

Input : 10
Output : 1
1 + 0 = 1, so only one times 
an number can be replaced by its sum .

Input : 991
Output : 3
9 + 9 + 1 = 19, 1 + 9 = 10, 1 + 0 = 1 
hence 3 times the number can be replaced 
by its sum.

我们已经讨论了寻找一个数字的总和，直到总和变成一位数字。
这里的问题只是上述先前问题的扩展。在这里，我们只想计算一个数字可以用其总和替换的次数，直到它只包含一位数字为止。由于数字可能非常大，为避免溢出，我们将数字输入为字符串。因此，为了计算该值，我们使用一个名为suspend_sum的变量，在该变量中，我们反复计算字符串的位数之和，然后再次将该temporary_sum转换为字符串 。重复此过程，直到字符串长度变为1为止。为了更清楚地说明这一点，请考虑编号991
9 + 9 + 1 = 19，现在19是一个字符串
1 + 9 = 10，同样10是一个字符串
1 + 0 = 1。同样，1是一个字符串，但是这里的字符串长度是1，所以循环中断。
求和运算的数量是最终答案。
以下是此方法的实现。

C++

// C++ program to count number of times we
// need to add digits to get a single digit.
#include 
using namespace std;
 
int NumberofTimes(string str)
{
    // Here the count variable store
    // how many times we do sum of
    // digits and temporary_sum
    // always store the temporary sum
    // we get at each iteration .
    int temporary_sum = 0, count = 0;
 
    // In this loop we always compute
    // the sum of digits in temporary_
    // sum variable and convert it
    // into string str till its length
    // become 1 and increase the count
    // in each iteration.
    while (str.length() > 1)
    {
        temporary_sum = 0;
 
        // computing sum of its digits
        for (int i = 0; i < str.length(); i++)
            temporary_sum += ( str[ i ] - '0' ) ;
 
        // converting temporary_sum into string
        // str again .
        str = to_string(temporary_sum) ;
 
        // increase the count
        count++;
    }
 
    return count;
}
 
// Driver program to test the above function
int main()
{
    string s = "991";
    cout << NumberofTimes(s);
    return 0;
}

Java

// Java program to count number of times we
// need to add digits to get a single digit.
 
public class GFG
{
    static int NumberofTimes(String str)
    {
        // Here the count variable store
        // how many times we do sum of
        // digits and temporary_sum
        // always store the temporary sum
        // we get at each iteration .
        int temporary_sum = 0, count = 0;
      
        // In this loop we always compute
        // the sum of digits in temporary_
        // sum variable and convert it
        // into string str till its length
        // become 1 and increase the count
        // in each iteration.
        while (str.length() > 1)
        {
            temporary_sum = 0;
      
            // computing sum of its digits
            for (int i = 0; i < str.length(); i++)
                temporary_sum += ( str.charAt(i) - '0' ) ;
      
            // converting temporary_sum into string
            // str again .
            str = temporary_sum + "" ;
      
            // increase the count
            count++;
        }
      
        return count;
    }
     
    // Driver program to test above functions
    public static void main(String[] args)
    {
         String s = "991";
         System.out.println(NumberofTimes(s));
    }
 
}
/* This code is contributed by Mr. Somesh Awasthi */

Python3

# Python 3 program to count number of times we
# need to add digits to get a single digit.
def NumberofTimes(s):
 
    # Here the count variable store
    # how many times we do sum of
    # digits and temporary_sum
    # always store the temporary sum
    # we get at each iteration .
    temporary_sum = 0
    count = 0
 
    # In this loop we always compute
    # the sum of digits in temporary_
    # sum variable and convert it
    # into string str till its length
    # become 1 and increase the count
    # in each iteration.
    while (len(s) > 1):
     
        temporary_sum = 0
 
        # computing sum of its digits
        for i in range(len(s)):
            temporary_sum += (ord(s[ i ]) -
                              ord('0'))
 
        # converting temporary_sum into
        # string str again .
        s = str(temporary_sum)
 
        # increase the count
        count += 1
 
    return count
 
# Driver Code
if __name__ == "__main__":
     
    s = "991"
    print(NumberofTimes(s))
 
# This code is contributed by Ita_c

C#

// C# program to count number of
// times we need to add digits to
// get a single digit.
using System;
 
class GFG {
     
    // Function to count number of
    // times we need to add digits
    // to get a single digit
    static int NumberofTimes(String str)
    {
         
        // Here the count variable store
        // how many times we do sum of
        // digits and temporary_sum
        // always store the temporary sum
        // we get at each iteration .
        int temporary_sum = 0, count = 0;
     
        // In this loop we always compute
        // the sum of digits in temporary_
        // sum variable and convert it
        // into string str till its length
        // become 1 and increase the count
        // in each iteration.
        while (str.Length > 1)
        {
            temporary_sum = 0;
     
            // computing sum of its digits
            for (int i = 0; i < str.Length; i++)
                temporary_sum += (str[i] - '0');
     
            // converting temporary_sum
            // into string str again .
            str = temporary_sum + "" ;
     
            // increase the count
            count++;
        }
     
        return count;
    }
     
    // Driver code
    public static void Main()
    {
        String s = "991";
        Console.Write(NumberofTimes(s));
    }
 
}
 
// This code is contributed by Nitin Mittal.

PHP

 1)
    {
        $temporary_sum = 0;
 
        // computing sum of its digits
        for ($i = 0; $i < strlen($str); $i++)
            $temporary_sum += ($str[ $i ] - '0');
 
        // converting temporary_sum into
        // string str again .
        $str = (string)($temporary_sum);
 
        // increase the count
        $count++;
    }
 
    return $count;
}
 
// Driver Code
$s = "991";
echo NumberofTimes($s);
 
// This code is contributed
// by Akanksha Rai
?>

Javascript

 
// Javascript program to
// count number of times we
// need to add digits to
// get a single digit.
 
function NumberofTimes(str)
{
    // Here the count variable store
    // how many times we do sum of
    // digits and temporary_sum
    // always store the temporary sum
    // we get at each iteration .
    var temporary_sum = 0, count = 0;
  
    // In this loop we always compute
    // the sum of digits in temporary_
    // sum variable and convert it
    // into string str till its length
    // become 1 and increase the count
    // in each iteration.
    while (str.length > 1)
    {
        temporary_sum = 0;
  
        // computing sum of its digits
        for (i = 0; i < str.length; i++)
         temporary_sum += ( str.charAt(i) - '0' ) ;
  
        // converting temporary_sum into string
        // str again .
        str = temporary_sum + "" ;
  
        // increase the count
        count++;
    }
  
    return count;
}
 
// Driver program to test above functions
var s = "991";
document.write(NumberofTimes(s));
 
// This code contributed by Princi Singh
 

输出：

3