Merge branch 'master' of ssh://github.com/Perilynn/HackerRank-Coding-Challenges

Author: andrewyang96

Fun Problems/Rohan.java

@@ -0,0 +1,22 @@
+import java.lang.*;
+import java.util.*;
+
+public class FunProblems {
+    int toInt(String str) {
+        return Integer.parseInt(str);
+    }
+
+    String toString(double x) {
+        return String.valueOf(x);
+    }
+
+    boolean isNumber(String str) {
+        try {
+            double x = Double.parseDouble(str);
+        } catch(NumberFormatException e) {
+            return false;
+        }
+
+        return true;
+    }
+}

Fun Problems/aravind.cpp

@@ -104,4 +104,64 @@ void FillSiblingVector(node* root) {
             children[i]->siblings.push_back(children[j]);
         }
     }
+}
+
+/* 
+Convert string to int manually, and convert an int to a string manually
+*/
+
+int ToInt(string input) {
+    int val = 0;
+    for(int i = 0; i < input.size(); i++) value += (input[i] = '0') * pow(10, input.size() - i - 1);
+    return value;
+}
+
+string ToString(int input) {
+    bool isNeg = input < 0;
+    if(input == 0) return "0";
+    string value = "";
+    while(input != 0) {
+        value += pow(-1, negative) * (input % 10) + '0';
+        input /= 10;
+    }
+    if(negative) value += '-';
+    return Reverse(value);
+}
+
+
+
+/*
+Boolean function isNumber. given a string, return true if it is a
+valid number, return false if not. dont forget to account negatives
+and decimals
+*/
+
+bool IsNumber(string number) // no fractions
+{
+  bool foundDecimal = false;
+  int i = 0;
+  if (number[0] == '-')
+  {
+    i++;
+  }
+
+  for ( ; i < number.size(); i++)
+  {
+    if (number[i] == '.')
+    {
+      if (foundDecimal)
+      {
+        return false;
+      }
+      else
+      {
+        foundDecimal = true;
+      }
+    }
+    else if (!isdigit(number[i]))
+    {
+      return false;
+    }
+  }
+  return true;
 }

README.md

@@ -52,7 +52,7 @@ git push origin master
   * insert <5,8> gets <4,8><10,15><20,21>
   * insert <16,17> gets <4,8><10,15><16,17><20,21>
   * insert <1,30> gets <1,30>
-3. In a tree of nodes, where each node is defined as
+4. In a tree of nodes, where each node is defined as
 ```
 class node
 {
@@ -65,3 +65,24 @@ class node
 assume given a tree, all nodes have their children vectors filled.
 fill their siblings vector
 
+5.
+Convert string to int manually, and convert an int to a string manually
+
+E.x. "123" (type string) to 123 (type int)
+
+and 123 (type int) to "123" (type string)
+(boilerplate c++ example)
+```
+int toInt(string x) {
+  //your code here
+}
+
+string toString(int x) {
+  //your code here
+}
+```
+
+6. 
+Boolean function isNumber. given a string, return true if it is a
+valid number, return false if not. dont forget to account negatives
+and decimals