Useful links

* https://blog.algomaster.io/p/how-i-mastered-data-structures-and-algorithms

* https://blog.algomaster.io/p/15-leetcode-patterns

* https://blog.algomaster.io/p/resources-for-big-tech-interviews

I have failed Google coding interview today, let's save it here.

I applied to google jobs from careers page, and hr reached out to me. We had a call and he gave me a mock google interview. Mock interview was fine, got some positive feedback, but as usual couldn't solve the problem. Then a real assesment interview started and I failed from the first problem below:

The problem:
input is a list of ranges
[[2,4],[4,5],[4,5]]

output - all possible numbers by concatinating numbers from ranges
244, 245, ..., 344

to be clear:
Input:
A list of ranges, where each range is represented as a 2-element array [start, end] (inclusive).
Example: [[2, 4], [4, 5], [4, 5]]

Output:
An array of strings. Each string represents a number formed by picking one digit from each range in the given order.
Example Output for above input:
["244", "245", "254", "255", "344", "345", "354", "355", "444", "445", "454", "455"]



The solution I wrote:
const findNumbers = (ranges) =>{
  let rangeLength = ranges.length;
    
  const buildCombination(arr, r, path){
    let res = []
    if(r === rangeLength){
      res.push(path)
      return res
    }

    for(let i=arr[0]; i<= arr[arr.length-1]; i++){
      path = ${path}${i}
      buildCombination(ranges[r+1], r+1, path)
     
    }
  }
  
  return buildCombination(ranges[0], 0, '')
  
}