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  1. Prepare
  2. Algorithms
  3. Recursion
  4. Recursive Digit Sum
  5. Discussions

Recursive Digit Sum

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821 Discussions

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  • hack_56845
     + 0 comments

    public static int sum(String n) { int j = n.length(); if(j == 1) { return n.charAt(0)-'0'; } if(j <= 0) { return 0; } return (n.charAt(j-1)-'0')+ sum(n.substring(0,j-1)); }

    public static int superDigit(String n, int k) {
int sum = 0;
int total = 0;
// Write your code here
    if ((k == 1) && n.length() == 1) {
        return (int) Integer.valueOf(n);
    } 
    else {
        for(int i = 0; i< n.length(); i++ ) {
            sum = (n.charAt(i)-'0') * k;
            int j = sum(String.valueOf(sum));
            if(j < 10) {
                total += j;
            } else {
                total += superDigit(String.valueOf(sum),1);
            }  
        }
    }
    return total < 10 ? total:superDigit(String.valueOf(total),1) ;   
}

    }

  • yumingjing7
     + 0 comments

    c#

        public static int superDigit(string n, int k)
    {
        long start = 0;
        for(int i = 0; i < n.Length; i++)
        {
            start += (n[i] - '0');
        }
        start = start * k;
        return (int)backtrack(start);
    }
    static long backtrack(long num)
    {
        if(num <= 9) return num;
        long res = 0;
        while(num > 0)
        {
            res += num % 10;
            num = num / 10;
        }
        return backtrack(res);
    }

  • vasilisgoutz08
     + 0 comments

    Javascript

    function superDigit(n, k) {
  if(n.length == 1){
    return n;
  }
  else {
    let sum = getSum(n) * k;
    sum = sum.toString();
    return superDigit(sum, 1);
  }
}

function getSum(n) {
  return n.split('').map(el => parseInt(el)).reduce((acc, curr) => acc + curr, 0);
}

  • bsnagarjun90
     + 0 comments

    Python

    def superDigit(n, k):
    # Write your code here
    num = str(sum([int(i) for i in str(n)])) * k
    
    def rec(num):
        if len(str(num)) == 1:
            return num
        
        return rec(str(sum([int(i) for i in num])))
        
    return rec(num)

  • faixz
     + 0 comments
    def superDigit(n, k):
    # Write your code here
    digit = sum(int(i) for i in n)
    total = digit*k
    return helper(total)
    
def helper(num):
    if num<10:
        return num
    s = sum(int(i) for i in str(num))
    return helper(s)