made slight changes in code and added some description

Author: anishsingh20

Data Structures/Stacks/InfixToPostfix.cpp

@@ -31,12 +31,12 @@ string InfixToPostfix(string exp)
 	//if delimitter continue
 		if(exp[i]==' ' || exp[i]==',') continue;
 
-		//if operator neing scanned has lower or equal precedence than alraedy in stack , 
+		//if operator being scanned has lower or equal precedence than alraedy in stack , 
 		//pop all with higher precedence
 		// push low precedence into stack
 		else if(isOperator(exp[i])) {
 			while(!S.empty() && S.top()!='(' && checkHighPrecedence(S.top(),exp[i])) {
-				postfix += S.top(); //add higher precedence opt to stack
+				postfix += S.top(); //add higher precedence opt to postfix expression
 				S.pop(); //pop higher precedence opt from stack	
 			}
 			//push lower precedence scanned opt to stack

Data Structures/Stacks/reverseStringUsingStack.cpp

@@ -6,21 +6,51 @@ using namespace std;
 
 //------------------------USING STACK-------------------- takes Time coplexity=O(n),space complexity=O(n) due to space allocated for stack
 
+//void reverse(string str) {
+//	stack<char> s;
+//	
+//	//push string to stack
+//	//reading the string char one by one and pusing it to stack
+//	for(int i=0;i<str.length();i++) {
+//		s.push(str[i]);
+//	}
+//	
+//	//popping the chars and revrrsing
+//	for(int i=0; i<str.length();i++) {
+//		str[i] = s.top(); //storing top element of stack in str,reversal
+//		s.pop(); //popping
+//	}
+//	cout<<str; //string is now updated and reversed
+//}
+
+//int main() {
+//	string name;
+//	getline(cin,name);
+//	reverse(name);
+//	
+//	return 0;
+//}
+
+//TIME COMPLEXITY=o(n) AND SPACE COMPLEXITY= O(1) , n = size of string for the below method
+
 void reverse(string str) {
-	stack<char> s;
 
-	//push string to stack
-	//reading the string char one by one and pusing it to stack
-	for(int i=0;i<str.length();i++) {
-		s.push(str[i]);
-	}
+	int i = 0;
+	int j = str.length()-1;
+	
+	
+//	if(i==j) {
+//		return;
+//	}
 
-	//popping the chars and revrrsing
-	for(int i=0; i<str.length();i++) {
-		str[i] = s.top(); //storing top element of stack in str,reversal
-		s.pop(); //popping
+	while(i<j) {
+		
+		swap(str[i],str[j]); //swapping 
+		i++;
+		j--;
 	}
-	cout<<str; //string is now updated and reversed
+	
+	cout<<str; //now str is updated with new reversed value	
 }
 
 int main() {
@@ -31,36 +61,6 @@ int main() {
 	return 0;
 }
 
-//TIME COMPLEXITY=o(n) AND SPACE COMPLEXITY= O(1) , n = size of string for the below method
-
-//void reverse(string str) {
-//	
-//	int i = 0;
-//	int j = str.length()-1;
-//	
-//	
-////	if(i==j) {
-////		return;
-////	}
-//	
-//	while(i<j) {
-//		
-//		swap(str[i],str[j]); //swapping 
-//		i++;
-//		j--;
-//	}
-//	
-//	cout<<str; //now str is updated with new reversed value	
-//}
-//
-//int main() {
-//	string name;
-//	getline(cin,name);
-//	reverse(name);
-//	
-//	return 0;
-//}
-