Last Updated: 18 Feb, 2021
2’s Complement
Easy
Asked in companies
Given a binary string of length ‘N’, find its 2’s complement.
A binary string contains only ‘0’ or ‘1’.
2’s complement is 1’s complement + 1.
For example, 2’s complement of 00000101 is 11111011.
Input format :
The first line of input contains an integer T denoting the number of test cases.
The next line contains a string of length N.
Output format :
For each test case, print the 2’s complement of the given string in a separate line.
Note :
You don’t have to print anything; it has already been taken care of. Just implement the given function.
Constraints :
1 <= T <= 5
1 <= N <= 20
where ‘T’ is the total number of test cases, and N is the length of the string.
Time Limit : 1sec
Approaches
For 2’s complement :
- Find one’s complement.
- Traverse the one’s complement starting from LSB (least significant bit) and look for 0.
- Flip all 1’s (change to 0) until we find a ‘0’. Finally, we will flip that first 0.
For 2’s Complement :
- Traverse the string from last till the single 1 is not traversed.
- and after that flip all values of the string i.e. 0 to 1 and 1 to 0.
- Return the string.