Pebble Technology Embedded Software Engineer interview questions

It was a hangout interview. He asked me to code on code edit. I was given a code and asked to write a solution in any language of my preference. I chose C. The crucial part here is when you encounter a 0 in a column for the first time, you make that column 0 as well as the row 0. But one consideration is we dont have to forget the 0s in the same column or row that might be there to make the corresponding rows/collumns 0s too.