Tesco Interview Experience DSA

Round 1: DSA

Questions:

1. Understanding of the problem statement of the task.
2. How was it solved?
3. What was your role and what features did you work on?
4. There was a heavy focus on testing. What was the code coverage of this project?
5. What tools were used to identify the code coverage?
6. How was the PR review process?
7. How are security bugs handled?
8. How will you sell your point of view if you come up with a new solution? (Expected answer: using performance benchmarking)
9. How was the functional correctness of the project ensured when anyone raises a new PR?

DSA Problem:

• In a store, a colleague can work for multiple departments. Here are shifts of a colleague in various departments:
  • In Bakery department: From 10 to 12
  • In Checkout department: From 12 to 14
  • In Dairy department: From 15 to 19
• Given the above split of shifts, provide an API/method to return the different shifts of a colleague for the day after merging contiguous shifts. This will be exposed to the colleague in different UI and help them plan their day accordingly.
• Sample Output: Shift timings in this case are 10 to 14 and 15 to 19.

public static void booleanMergeInterval(int [][] intervals){
    boolean [] time = new boolean [25];
    List<int []> result = new ArrayList<>();
    for(int i = 0; i< intervals.length;i++){
        int start = intervals[i][0];
        int end = intervals[i][1];
        while(start<end){
            time[start]=true;
            start++;
        }
    }

    for(int i = 1; i< 25;i++){
        int start = 0;
        int end = 0;
        if(time[i]==true){
            start= i;
            while(time[i]==true){
                i++;
            }
            end = i;
            result.add(new int []{start,end});
        }
    }

    for(int [] inter : result){
        System.out.println("Intervals are "+inter[0]+" ,"+inter[1]);
    }
}

Final Questions:

• Why Tesco?

Recommendations for Future Candidates:

1. Interval problems - commonly seen in interviews.
2. Merging sorted lists.
3. K sorted lists.
4. Sorting Linked Lists.

• Brush up on testing; I had read about Test Coverage for the code as well.