DSA - 1 new - Word Search (DFS + Backtracking)

79. Word Search

Grid traversal + backtracking problem.

Insight

• Traverse the matrix using DFS.
• At each cell:
  • Match current character.
  • Explore all 4 directions (up, down, left, right).
• Use backtracking to revert state after exploring paths.
• Key Optimization: Instead of maintaining a separate visited matrix:
  • Mark the current cell as '#' (visited).
  • Restore it after DFS call (backtrack). This reduces extra space and keeps logic tight.

⚡ JS Refreshers

• Strings are immutable → cannot modify in-place.
• splice() works only on arrays, not strings.
• Know CRUD operations by heart on these structures: Map, Set, Object, Array