From 0256f9edd8ce62e78de3d6703701a5e91ab21e08 Mon Sep 17 00:00:00 2001
From: Christian Bender <christianbender89@web.de>
Date: Tue, 27 Mar 2018 18:51:25 +0200
Subject: [PATCH] improved the code and put in some comments

---
 Others/String Fibonacci.cpp | 55 +++++++++++++++++++++++--------------
 1 file changed, 34 insertions(+), 21 deletions(-)

diff --git a/Others/String Fibonacci.cpp b/Others/String Fibonacci.cpp
index 77571b93a..44d5d5748 100644
--- a/Others/String Fibonacci.cpp	
+++ b/Others/String Fibonacci.cpp	
@@ -8,65 +8,78 @@
 
 using namespace std;
 
-string add(string a, string b) 
-{ 
+string add(string a, string b)
+{
     string temp = "";
-    while ((int)a.length() < (int)b.length()) 
+
+    // carry flag
+    int carry = 0;
+
+    // fills up with zeros
+    while ((int)a.length() < (int)b.length())
     {
         a = "0" + a;
     }
-    while ((int)b.length() < (int)a.length()) {
+
+    // fills up with zeros
+    while ((int)b.length() < (int)a.length())
+    {
         b = "0" + b;
     }
-    int carry = 0;
-    for (int i = a.length() - 1; i >= 0; i--) 
+
+    // adds the numbers a and b
+    for (int i = a.length() - 1; i >= 0; i--)
     {
         char val = (char)(((a[i] - 48) + (b[i] - 48)) + 48 + carry);
-        if (val > 57) 
+        if (val > 57)
         {
             carry = 1;
             val -= 10;
         }
-        else 
+        else
         {
             carry = 0;
         }
         temp = val + temp;
     }
-    if (carry != 0) 
+
+    // processes the carry flag
+    if (carry == 1)
     {
         temp = "1" + temp;
     }
-    while (temp[0] == '0' && temp.length() != 1) 
+
+    // removes leading zeros.
+    while (temp[0] == '0' && temp.length() > 1)
     {
         temp = temp.substr(1);
     }
+
     return temp;
 }
 
-void fib_Accurate(long long n) 
+void fib_Accurate(long long n)
 {
     string tmp = "";
     string fibMinus1 = "1";
     string fibMinus2 = "0";
-        for (long long i = 0; i < n; i++) 
-        {
-            tmp = add(fibMinus1, fibMinus2);
-            
-            fibMinus2 = fibMinus1;
-            fibMinus1 = tmp;
-    	}
+    for (long long i = 0; i < n; i++)
+    {
+        tmp = add(fibMinus1, fibMinus2);
+        fibMinus2 = fibMinus1;
+        fibMinus1 = tmp;
+    }
     cout <<  fibMinus2;
 }
 
 
-int main() 
+int main()
 {
     int n;
     cout << "Enter whatever number N you want to find the fibonacci of\n";
     cin >> n;
     cout << n << " th Fibonacci is \n";
-	  fib_Accurate(n);
-    
+    fib_Accurate(n);
+
 	return 0;
 }