Preparation guide
Walmart Coding Questions
Overview
Practice Walmart coding questions in the style candidates report for online assessments and technical interviews. Focus: heaps, grids/BFS, intervals, ranking.
Walmart coding pattern
| Item | Typical expectation |
|---|---|
| Problems | 1-3 coding tasks depending on drive |
| Skills | heaps, grids/BFS, intervals, ranking |
| Languages | Java, C++, Python (confirm invite) |
| Bar | Correctness first, then complexity |
Practice problems
Question 1: inventory low-stock alerts
Show approach
Approach: Hash map thresholds + stream updates.
Map<Integer, Integer> map = new HashMap<>();for (int i = 0; i < nums.length; i++) { // fill logic}Complexity: State time/space before coding. Test empty input and single-element cases.
Question 2: assign nearest delivery partner
Show approach
Approach: Brute force or spatial heuristics; state complexity.
from collections import defaultdictdef solve(arr): # fill logic return arrComplexity: State time/space before coding. Test empty input and single-element cases.
Question 3: max orders in time window t
Show approach
Approach: Sort + two pointers.
Map<Integer, Integer> map = new HashMap<>();for (int i = 0; i < nums.length; i++) { // fill logic}Complexity: State time/space before coding. Test empty input and single-element cases.
Question 4: merge overlapping discount intervals
Show approach
Approach: Sort + merge.
from collections import defaultdictdef solve(arr): # fill logic return arrComplexity: State time/space before coding. Test empty input and single-element cases.
Question 5: top-k selling skus
Show approach
Approach: Count + heap.
Map<Integer, Integer> map = new HashMap<>();for (int i = 0; i < nums.length; i++) { // fill logic}Complexity: State time/space before coding. Test empty input and single-element cases.
Question 6: can rider reach customer on grid
Show approach
Approach: BFS on open cells.
from collections import defaultdictdef solve(arr): # fill logic return arrComplexity: State time/space before coding. Test empty input and single-element cases.
Question 7: cart coupon stacking rules
Show approach
Approach: Greedy with careful constraints.
Map<Integer, Integer> map = new HashMap<>();for (int i = 0; i < nums.length; i++) { // fill logic}Complexity: State time/space before coding. Test empty input and single-element cases.
Pattern drill plan (2 weeks)
| Day | Drill |
|---|---|
| Mon | Arrays + hashing (2 problems) |
| Tue | Two pointers / sliding window |
| Wed | Stacks / strings |
| Thu | Trees or graphs basics |
| Fri | Timed mock (2 problems / 90 min) |
| Sat | Re-solve Friday misses cold |
| Sun | Light CS theory + rest |
Common coding mistakes
- Coding before reading constraints
- Passing samples but failing hidden tests
- Silent complexity (cannot explain Big-O in interview)
- Switching languages mid-prep
- Never practicing on the real OA editor style

