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Word Search II

Understand how to use trie data structures to efficiently search for multiple words in a 2D grid of letters. This lesson guides you through implementing a solution that finds strings formed by adjacent cells, enhancing your problem-solving skills in coding interviews.

Statement

You are given a list of strings that you need to find in a 2D grid of letters such that the string can be constructed from letters in sequentially adjacent cells. The cells are considered sequentially adjacent when they are neighbors to each other either horizontally or vertically. The solution should return a list containing the strings from the input list that were found in the grid.

Constraints:

  • 11 \leq rows, columns 12\leq 12
  • 11 \leq words.length 3×103\leq 3 \times {10^3}
  • 11 \leq words[i].length 10\leq 10
  • grid[i][j] is an uppercase English letter.
  • words[i] consists of uppercase English letters.
  • All the strings are unique.

Note: The order of the strings in the output does not matter.

Examples

Understand the problem

Let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

Word Search II

1.

From the given list of words, which words are present in the grid?

OAACETAEIHKSIZLD\begin{matrix} O & A & A & C\\ E & T & A & E\\ I & H & K & S\\ I & Z & L & D \end{matrix}

[OATH,PEA,EAT][OATH, PEA, EAT]

A.

[EAT, OATH]

B.

[EAT, PEA]

C.

[OATH, PEA]

D.

[PEA]


1 / 3

Figure it out!

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Sequence - Vertical
Drag and drop the cards to rearrange them in the correct sequence.

1
2
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5

Try it yourself

Implement your solution in main.go in the following coding playground.

Go
usercode > main.go
package main
func findStrings(grid [][]rune, words []string) []string {
// Replace this placeholder return statement with your code
return make([]string, 0)
}
Word Search II