diff --git a/Datastructures/Linked List.cpp b/Datastructures/Linked List.cpp
index 02a2523ee..5abebd584 100644
--- a/Datastructures/Linked List.cpp	
+++ b/Datastructures/Linked List.cpp	
@@ -101,7 +101,7 @@ int main()
 		cout<<"\n2. Delete";
 		cout<<"\n3. Search";
 		cout<<"\n4. Print";
-		cout<<"\n5. Exit";
+		cout<<"\n0. Exit";
 		cout<<"\n\nEnter you choice : ";
 		cin>>choice; 
 		switch (choice)
@@ -115,8 +115,8 @@ int main()
 			case 3 : 	cout<<"\nEnter the element to be searched : ";
 						cin>>x;
 						search(x); 	break;
-			case 4 : show();	break;
-			case 5 : exit(0);
+			case 4 : 	show();	
+					cout<<"\n";	break;
 		}
 	}
 	while(choice!=0);
diff --git a/Datastructures/Stack Using Array.cpp b/Datastructures/Stack Using Array.cpp
index 944258ed4..c5ad146cb 100644
--- a/Datastructures/Stack Using Array.cpp	
+++ b/Datastructures/Stack Using Array.cpp	
@@ -1,12 +1,12 @@
 #include<iostream>
 using namespace std;
 
-int stack[10];
-int top=0;
+int *stack;
+int top=0, size;
 
 void push(int x)
 {
-	if(top==10)
+	if(top==size)
 	{
 		cout<<"\nOverflow";
 	}
@@ -42,6 +42,9 @@ void topmost()
 }
 int main()
 {
+	cout<<"\nEnter Size of stack : ";
+	cin>>size;
+	stack = new int[size];
 	int ch, x;
 	do
 	{
diff --git a/Decimal To Binary.cpp b/Decimal To Binary.cpp
index 3794d2a96..b8eaba1f1 100644
--- a/Decimal To Binary.cpp	
+++ b/Decimal To Binary.cpp	
@@ -1,20 +1,24 @@
-#include<iostream>
+// This function convert decimal to binary number 
+//
+#include <iostream>
 using namespace std;
+
 int main()
 {
 	int number;
-	cin>>number;
-	int remainder,binary=0,var=1;
-
-do{
-		
-	 remainder=number%2;
-	number=number/2;
-	binary=binary+(remainder*var);
-	var=var*10;
+	cout << "Enter a number:";
+	cin >> number;
+	int remainder, binary = 0, var = 1;
 
+	do {
+		remainder = number % 2; 
+		number = number / 2; 
+		binary = binary + (remainder*var); 
+		var = var * 10;
 
-}
-while(number>0);
-	cout<<binary;
+	} while (number>0);
+	cout << "the binary is :";
+	cout << binary;
+	cout << endl;
+	return 0;
 }
diff --git a/Decimal To Hexadecimal .cpp b/Decimal To Hexadecimal .cpp
index fadddfd74..39333ca00 100644
--- a/Decimal To Hexadecimal .cpp	
+++ b/Decimal To Hexadecimal .cpp	
@@ -2,50 +2,25 @@
 
 using namespace std;
 
-void main(void)
-{
+int main(void){
 	int valueToConvert = 0; //Holds user input
 	int hexArray[8];       //Contains hex values backwards
 	int i = 0;             //counter
-	int lValue = 0;       //Last Value of Hex result
+	char HexValues[] = "0123456789ABCDEF";
 
 	cout << "Enter a Decimal Value" << endl; //Displays request to stdout
 	cin >> valueToConvert;					        //Stores value into valueToConvert via user input
 
-	while (valueToConvert > 0)        //Dec to Hex Algorithm
-	{
-		lValue = valueToConvert % 16;        //Gets remainder
-		valueToConvert = valueToConvert / 16;
-		hexArray[i] = lValue;             //Stores converted values into an array
-		i++;
+	while (valueToConvert > 15){        //Dec to Hex Algorithm
+		hexArray[i++] = valueToConvert % 16;        //Gets remainder
+		valueToConvert /= 16;
 	}
+	hexArray[i] = valueToConvert;        //Gets last value
+	
 	cout << "Hex Value: ";
-	while (i > 0)
-	{
-		//Displays Hex Letters to stdout
-		switch (hexArray[i - 1]) {
-			case 10:
-				cout << "A"; 
-				break;
-			case 11:
-				cout << "B";
-				break;
-			case 12:
-				cout << "C";
-				break;
-			case 13:
-				cout << "D";
-				break;
-			case 14: 
-				cout << "E";
-				break;
-			case 15:
-				cout << "F";
-				break;
-			default:
-				cout << hexArray[i - 1]; //if not an int 10 - 15, displays int value
-		}
-			i--;
-	}
+	while (i >= 0)
+		cout<<HexValues[hexArray[i--]];
+	
 	cout << endl;
+	return 0;
 }
diff --git a/Dynamic Programming/Edit Distance.cpp b/Dynamic Programming/Edit Distance.cpp
index d99d03c5a..ff0d3fe19 100644
--- a/Dynamic Programming/Edit Distance.cpp	
+++ b/Dynamic Programming/Edit Distance.cpp	
@@ -30,7 +30,7 @@ int editDist(string str1, string str2, int m, int n) {
     
         //If last characters are same then continue
         //for the rest of them.
-        if(str1[m-1] == str2[n-2])
+        if(str1[m-1] == str2[n-1])
             return editDist(str1, str2, m-1, n-1);
 
         //If last not same, then 3 possibilities
@@ -63,7 +63,7 @@ int editDistDP(string str1, string str2, int m, int n) {
 
             //If character same. Recur for remaining 
             else if(str1[i-1] == str2[j-1])
-                dp[i][j] == dp[i-1][j-1];
+                dp[i][j] = dp[i-1][j-1];
 
             else
                 dp[i][j] = 1 + min(dp[i][j-1],//Insert
@@ -80,8 +80,8 @@ int main() {
     string str1 = "sunday";
     string str2 = "saturday";
     
-    cout << editDist(str1, str1, str1.length(), str2.length()) << endl;
-    cout << editDistDP(str1, str1, str1.length(), str2.length()) << endl;
+    cout << editDist(str1, str2, str1.length(), str2.length()) << endl;
+    cout << editDistDP(str1, str2, str1.length(), str2.length()) << endl;
 
     return 0;
 }
diff --git a/Happy_number.cpp b/Happy_number.cpp
index f3571ac34..f8e518403 100644
--- a/Happy_number.cpp
+++ b/Happy_number.cpp
@@ -2,6 +2,7 @@
   and this sum turns out to be 1 */
 #include <iostream>
 using namespace std;
+
 int main()
 {
   int n,k,s=0,d;
@@ -23,4 +24,5 @@ int main()
    cout << n << " is a happy number" << endl;
   else
    cout << n << " is not a happy number" << endl;
+  return 0;
 }
diff --git a/Others/Paranthesis Matching.cpp b/Others/Paranthesis Matching.cpp
index 0347f38d0..25ee7287b 100644
--- a/Others/Paranthesis Matching.cpp	
+++ b/Others/Paranthesis Matching.cpp	
@@ -1,52 +1,63 @@
 #include<iostream>
-#include<stdlib.h>
 #include<string>
-#include<stdio.h>
+
 using namespace std;
 
-const int MAX = 100;
+#define MAX 100
 
 // -------------- stack --------------
 
 char stack[MAX];
-int top=0;
+int top = -1;
 
-void push(char ch)
-{
-	stack[top++]=ch;
+void push(char ch){
+	stack[ ++top ] = ch;
 }
 
-char pop()
-{
-	return stack[--top];
+char pop(){
+	return stack[ top-- ];
 }
 
 // -------------- end stack -----------
 
-int main()
-{
+char opening(char ch){
+	switch(ch){
+		case '}':
+			return '{';
+		case ']':
+			return '[';
+		case ')':
+			return '(';
+		case '>':
+			return '<';		
+	}
+}
+
+int main(){
+
 	string exp;
+	int valid = 1, i = 0;
 	cout<<"Enter The Expression : ";
 	cin >> exp;
-	for (int i = 0; i < exp.length(); i++)
-	{
-			if (exp[i]=='(' || exp[i]=='{' || exp[i]=='[' || exp[i]=='<')
-			{
+	
+	while (valid == 1 && i < exp.length()){
+			if (exp[i] == '(' || exp[i] == '{' || exp[i] == '[' || exp[i] == '<'){
 				push(exp[i]);
 			}
-			else if (exp[i]==')' || exp[i]=='}' || exp[i]==']' || exp[i]=='>')
-			{
-                pop();
+			else if (top >= 0 && stack[top] == opening(exp[i])){
+				pop();
 			}
+			else{
+				valid = 0;
+			}
+			i++;
 	}
 
     // makes sure the stack is empty after processsing (above)
-	if(top==0)
-	{
-		cout<<"Correct Expression";
+	if (valid == 1 && top == -1){
+		cout<<"\nCorrect Expression";
 	}
-	else
-	{
+	else{
 		cout<<"\nWrong Expression";
 	}
 
diff --git a/Others/String Fibonacci.cpp b/Others/String Fibonacci.cpp
index 44d5d5748..8027b9668 100644
--- a/Others/String Fibonacci.cpp	
+++ b/Others/String Fibonacci.cpp	
@@ -81,5 +81,5 @@ int main()
     cout << n << " th Fibonacci is \n";
     fib_Accurate(n);
 
-	return 0;
+    return 0;
 }
diff --git a/README.md b/README.md
index e4ad41623..81367fcb4 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,8 @@ How you can contribute? See this small guide.
 
 * Use the directory structure of the repository.
 * Please describe your pull requests. 
-* Don't use **bits/stdc++.h** because this is quite Linux specific and slow down the compiler process.
-* Put in comments in your code.
-* Avoid **struct** uses instead the **class** keyword.
-* Add some test cases in the main-function.
\ No newline at end of file
+* Don't use **bits/stdc++.h** because this is quite Linux specific and slows down the compiler process.
+* Put comments in your code.
+* Avoid **struct**. Instead use the **class** keyword.
+* Add some test cases in the main-function.
+* Can suggest any change in present algorithms(if needed).
\ No newline at end of file
diff --git a/Sorting/Bubble Sort.cpp b/Sorting/Bubble Sort.cpp
index c94a45efc..fed01bfc5 100644
--- a/Sorting/Bubble Sort.cpp	
+++ b/Sorting/Bubble Sort.cpp	
@@ -1,39 +1,55 @@
 //Bubble Sort
 
 #include<iostream>
+#include<vector>
 using namespace std;
 
 int main()
 {
 	int n;
+	short swap_check=0;
+  	cout << "Enter the amount of numbers to sort: ";
 	cin >> n;
-	int Array[n];
-	cout<<"\nEnter any 6 Numbers for Unsorted Array : ";
+	vector<int> numbers;
+	cout << "Enter " << n << " numbers: ";
+	int num;
 
-	//Input
+  	//Input
 	for(int i=0; i<n; i++)
 	{
-		cin>>Array[i];
+		cin >> num;
+		numbers.push_back(num);
 	}
 
 	//Bubble Sorting
 	for(int i=0; i<n; i++)
 	{
-		for(int j=0; j<n-1; j++)
+		swap_check=0;
+		for(int j=0; j<n-1-i; j++)
 		{
-			if(Array[j]>Array[j+1])
+			if(numbers[j]>numbers[j+1])
 			{
-				int temp=Array[j];
-				Array[j]=Array[j+1];
-				Array[j+1]=temp;
+				swap_check=1;
+				swap(numbers[j], numbers[j+1]);
 			}
 		}
+		if(swap_check == 0)
+		{	
+			break;
+		}
 	}
 
 	//Output
 	cout<<"\nSorted Array : ";
-	for(int i=0; i<n; i++)
+	for(int i=0; i<numbers.size(); i++)
 	{
-		cout<<Array[i]<<"\t";
+		if(i != numbers.size() -1)
+		{
+			cout << numbers[i] << ", ";
+		}else
+		{
+			cout << numbers[i] << endl;
+		}
 	}
+  return 0;
 }
diff --git a/Sorting/Counting_Sort.cpp b/Sorting/Counting_Sort.cpp
new file mode 100644
index 000000000..bea604a98
--- /dev/null
+++ b/Sorting/Counting_Sort.cpp
@@ -0,0 +1,55 @@
+#include<iostream>
+using namespace std;
+
+int Max(int Arr[], int N){
+	int max = Arr[0];
+	for(int i=1; i<N; i++)
+		if(Arr[i] > max)
+			max = Arr[i];
+	return max;
+}
+
+int Min(int Arr[], int N){
+	int min = Arr[0];
+	for(int i=1; i<N; i++)
+		if(Arr[i] < min)
+			min = Arr[i];
+	return min;
+}
+
+void Print(int Arr[], int N){
+	for(int i=0; i<N; i++) cout<<Arr[i] <<", ";
+}
+
+int *Counting_Sort(int Arr[], int N){
+
+	int max = Max(Arr, N);
+	int min = Min(Arr, N);
+	int *Sorted_Arr = new int[N];
+	
+	int *Count = new int[max-min+1];
+	
+	for(int i=0; i<N; i++) Count[Arr[i]-min]++;
+  
+	for(int i=1; i<(max-min+1); i++) Count[i]+=Count[i-1];
+	
+	for(int i=N-1; i>=0; i--){
+		Sorted_Arr[Count[Arr[i]-min]-1] = Arr[i];
+		Count[Arr[i]-min]--;
+	}
+	
+	return Sorted_Arr;
+}
+
+int main(){
+
+	int Arr[] = {47, 65, 20, 66, 25, 53, 64, 69, 72, 22, 74, 25, 53, 15, 42, 36, 4, 69, 86, 19}, N = 20;
+	int *Sorted_Arr;
+	
+	cout<<"\n\tOrignal Array = ";Print(Arr, N);
+	Sorted_Arr = Counting_Sort(Arr, N);
+	cout<<"\n\t Sorted Array = ";Print(Sorted_Arr, N);
+	cout<<endl;
+	
+	return 0;
+}
diff --git a/Sorting/Insertion Sort.cpp b/Sorting/Insertion Sort.cpp
index 45e860dde..af66550ec 100644
--- a/Sorting/Insertion Sort.cpp	
+++ b/Sorting/Insertion Sort.cpp	
@@ -6,8 +6,10 @@ using namespace std;
 int main()
 {
 	int n;
+	cout<<"\nEnter the length of your array : ";
+	cin>>n;
 	int Array[n];
-	cout<<"\nEnter any 6 Numbers for Unsorted Array : ";
+	cout<<"\nEnter any "<<n<<" Numbers for Unsorted Array : ";
 	
 	//Input
 	for(int i=0; i<n; i++)
@@ -34,5 +36,6 @@ int main()
 	{
 		cout<<Array[i]<<"\t";
 	}
+  return 0;
 }
 
diff --git a/s[i] b/s[i]
deleted file mode 100644
index e69de29bb..000000000