Reverse the String
You are given a string 'STR'. The string contains [a-z] [A-Z] [0-9] [special characters]. You have to find the reverse of the string.

For example:

If the given string is: STR = "abcde". You have to print the string "edcba".

follow up:

Try to solve the problem in O(1) space complexity.

Input Format:

The first line of input contains a single integer 'T', representing the number of test cases or queries to be run. Then the 'T' test cases follow. The first and only line of each test case contains a string 'STR'.

Output Format:

For each test case, print a single line containing a single string denoting the reverse of the given string 'STR'. The output of each test case will be printed in a separate line.

Note:

You are not required to print the expected output, it has already been taken care of. Just implement the function.

Constraints:

1 ≤ T ≤ 10 1 ≤ |STR| ≤ 10 ^ 5 Where |STR| is the length of the string STR. Time limit: 1 sec.

Question

Reverse the String

You are given a string 'STR'. The string contains [a-z] [A-Z] [0-9] [special characters]. You have to find the reverse of the string.

For example:

 If the given string is: STR = "abcde". You have to print the string "edcba".

follow up:

Try to solve the problem in O(1) space complexity.

Input Format:

The first line of input contains a single integer 'T', representing the number of test cases or queries to be run. 

Then the 'T' test cases follow.

The first and only line of each test case contains a string 'STR'.

Output Format:

For each test case, print a single line containing a single string denoting the reverse of the given string 'STR'.

The output of each test case will be printed in a separate line.

Note:

You are not required to print the expected output, it has already been taken care of. Just implement the function.

Constraints:

1 ≤ T ≤ 10
1 ≤ |STR| ≤ 10 ^ 5 

Where |STR| is the length of the string STR.

Time limit: 1 sec.

Accepted Answer

Slicing can be used to reverse a string in python.
To reverse a string, we simply create a slice that starts with the length of the string, and ends at index 0.

To reverse a string using slicing, write:
stringname[stringlength::-1]

Accepted Answer

Optimal Solution

Traverse the string and swap the first character with the last character, the second character with the second last character and so on.
Basically, you need to swap the i-th character with the (N-i-1)-th character where N is the length of the string and 0-based indexing is considered.

Space Complexity: O(1)Explanation:

O(1).

In the worst case, only constant extra space is required.

Time Complexity: O(n)Explanation:

O(N), where ‘N’ is the length of the string.

Since we are iterating through the string only once, the overall time complexity is O(N).

Accepted Answer

First take the length of the given string. Using a for loop go from string length to 0 index in reverse manner. Then pick each chat from that index, append that in a new string.