Merge pull request #12 from AthulJoseph27/patch-3

Create RecursiveDigitSum.cpp

Author: swapnanildutta

CPP/RecursiveDigitSum.cpp

@@ -0,0 +1,161 @@
+/*
+We define super digit of an integer  using the following rules:
+
+Given an integer, we need to find the super digit of the integer.
+
+If  has only  digit, then its super digit is .
+Otherwise, the super digit of  is equal to the super digit of the sum of the digits of .
+For example, the super digit of  will be calculated as:
+
+	super_digit(9875)   	9+8+7+5 = 29 
+	super_digit(29) 	2 + 9 = 11
+	super_digit(11)		1 + 1 = 2
+	super_digit(2)		= 2  
+You are given two numbers  and . The number  is created by concatenating the string   times. Continuing the above example where , assume your value . Your initial  (spaces added for clarity).
+
+    superDigit(p) = superDigit(9875987598759875)
+                  5+7+8+9+5+7+8+9+5+7+8+9+5+7+8+9 = 116
+    superDigit(p) = superDigit(116)
+                  1+1+6 = 8
+    superDigit(p) = superDigit(8)
+All of the digits of  sum to . The digits of  sum to .  is only one digit, so it's the super digit.
+
+Function Description
+
+Complete the function superDigit in the editor below. It must return the calculated super digit as an integer.
+
+superDigit has the following parameter(s):
+
+n: a string representation of an integer
+k: an integer, the times to concatenate  to make 
+Input Format
+
+The first line contains two space separated integers,  and .
+
+Constraints
+
+Output Format
+
+Return the super digit of , where  is created as described above.
+
+Sample Input 0
+
+148 3
+Sample Output 0
+
+3
+Explanation 0
+
+Here  and , so .
+
+super_digit(P) = super_digit(148148148) 
+               = super_digit(1+4+8+1+4+8+1+4+8)
+               = super_digit(39)
+               = super_digit(3+9)
+               = super_digit(12)
+               = super_digit(1+2)
+               = super_digit(3)
+               = 3.
+Sample Input 1
+
+9875 4
+Sample Output 1
+
+8
+Sample Input 2
+
+123 3
+Sample Output 2
+
+9
+Explanation 2
+
+Here  and , so .
+
+super_digit(P) = super_digit(123123123) 
+               = super_digit(1+2+3+1+2+3+1+2+3)
+               = super_digit(18)
+               = super_digit(1+8)
+               = super_digit(9)
+               = 9
+*/
+
+#include <bits/stdc++.h>
+
+using namespace std;
+
+vector<string> split_string(string);
+
+// Complete the superDigit function below.
+int superDigit(string n, int k) {
+
+    if(n.size() == 1 && k == 1) return n[0]-'0';
+
+    long long sum = 0;
+    for(char c:n)
+        sum+=(c-'0');
+    
+    sum*=k;
+
+    while(sum > 10){
+        long long s = 0;
+        while(sum > 0){
+            s+=sum%10;
+            sum/=10;
+        }
+        sum = s;
+    }
+
+    return (int)sum;
+}
+
+int main()
+{
+    ofstream fout(getenv("OUTPUT_PATH"));
+
+    string nk_temp;
+    getline(cin, nk_temp);
+
+    vector<string> nk = split_string(nk_temp);
+
+    string n = nk[0];
+
+    int k = stoi(nk[1]);
+
+    int result = superDigit(n, k);
+
+    fout << result << "\n";
+
+    fout.close();
+
+    return 0;
+}
+
+vector<string> split_string(string input_string) {
+    string::iterator new_end = unique(input_string.begin(), input_string.end(), [] (const char &x, const char &y) {
+        return x == y and x == ' ';
+    });
+
+    input_string.erase(new_end, input_string.end());
+
+    while (input_string[input_string.length() - 1] == ' ') {
+        input_string.pop_back();
+    }
+
+    vector<string> splits;
+    char delimiter = ' ';
+
+    size_t i = 0;
+    size_t pos = input_string.find(delimiter);
+
+    while (pos != string::npos) {
+        splits.push_back(input_string.substr(i, pos - i));
+
+        i = pos + 1;
+        pos = input_string.find(delimiter, i);
+    }
+
+    splits.push_back(input_string.substr(i, min(pos, input_string.length()) - i + 1));
+
+    return splits;
+}