Generate all strings by expanding wildcards
Company: Bloomberg
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: medium
Interview Round: Onsite
## Problem
Given a string `s` consisting only of characters `'0'`, `'1'`, and `'*'`, replace every `'*'` with either `'0'` or `'1'` and return **all possible resulting binary strings**.
You may return the results in **any order**.
## Example
Input: `"01*"`
Output: `["010", "011"]`
Input: `"1*0*"`
Output: `["1000","1001","1100","1101"]`
Overview: This question evaluates algorithmic string manipulation and combinatorial enumeration skills, focusing on handling wildcard characters and generating all possible binary outcomes from a pattern.
Community answers
Answer by bansalmohit.217
For every character in the string:
If it's 0 or 1 → keep it and move to the next character.
If it's → we have 2 choices**:
Replace it with 0
Replace it with 1
Once we've processed the entire string, add the constructed string to the result.
Think of every as a decision point**.
function generateBinaryStrings(s) {
const results = [];
function backtrack(index, current) {
if(index === s.length){
results.push(current);
return;
}
if(s[index] === '0' || s[index] === '1'){
backtrack(index+1, current + s[index])
}
else{
backtrack(index+1, current + '0')
backtrack(index+1, current + '1')
}
}
backtrack(0, "")
return results;
}