Remove Consecutive Duplicates

Easy

0/40

37 upvotes

Asked in companies

Problem statement

For a given string(str), remove all the consecutive duplicate characters.

Example:

Input String: "aaaa"
Expected Output: "a"

Input String: "aabbbcc"
Expected Output: "abc"

The first and only line of input contains a string without any leading and trailing spaces. All the characters in the string would be in lower case.

Output Format:

The only line of output prints the updated string.

You are not required to print anything. It has already been taken care of.

Constraints:

0 <= N <= 10^6
Where N is the length of the input string.

Time Limit: 1 second

Constraints:

0 <= N <= 10^6
Where N is the length of the input string.

Time Limit: 1 second

aabccbaa

abcba

xxyyzxx

xyzx

Approaches (1)

Approach 1

Checking equality with last Character

Store the length of the String in a variable n.
We handle a simple corner case to avoid runtime error. This is when the length of the string is 0.
We append the character at position 0 as a simple base case.
For each consecutive run of equal characters, we only append the first character. This can be ensured simply by checking input[i-1] ≠ input[i].
For eg consider aaabbb. Only First instance of b will be appended to output since only this occurrence satisfies the condition input[i-1] ≠ input[i].
We do this until we reach the end of the string.
We return the final output string.

Time Complexity

Space Complexity

(100% EXP penalty)

Remove Consecutive Duplicates

Console