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Problem solution · Java

The Wording Game

The Wording Game: a Java solution using direct simulation. Learn the idea, check the complexity, and read the full code, with credit to walkccc LeetCode Solutions.

Technique
Direct simulation
Source
walkccc LeetCode Solutions
Length
35 lines
Start with the idea.

Try the problem first. If you get stuck, read the approach below, then write your own solution. The full code is at the bottom.

Approach

Direct simulation

For The Wording Game, the implementation follows the problem’s operations directly while maintaining only the state needed for the next decision.

  1. Translate each rule into one explicit state update.
  2. Maintain the invariant after every processed item.
  3. Return the accumulated state once all relevant input has been handled.

Code notes

  • 35 lines of Java from the credited upstream file 2868.java.
  • The implementation visibly relies on sequence storage.
  • 4 loop blocks detected.

Complexity

Count the number and nesting of passes over the input, then include the maintained containers in the memory estimate.

Check the problem constraints before deciding whether this complexity will pass.

Source

Code and credit

This code comes from walkccc LeetCode Solutions by P.-Y. Chen (walkccc) and is used under the MIT licence.

Open problem ↗Original source ↗
Full codeThe Wording Game · JavaJava
Use this to learn the idea, then write your own version.
class Solution {  public boolean canAliceWin(String[] a, String[] b) {    // words[0][i] := the biggest word starting with ('a' + i) for Alice    // words[1][i] := the biggest word starting with ('a' + i) for Bob    String[][] words = new String[2][26];     // For each letter, only the biggest word is useful.    for (final String word : a)      words[0][word.charAt(0) - 'a'] = word;     for (final String word : b)      words[1][word.charAt(0) - 'a'] = word;     // Find Alice's smallest word.    int i = 0;    while (words[0][i] == null)      ++i;     // Iterate through each letter until we find a winner.    // Start with Alice's turn (0), so it's Bob's turn (1) now.    for (int turn = 1; true; turn = turn ^ 1)      // If the current player has a word that having the letter that is greater      // than the opponent's word, choose it.      if (words[turn][i] != null && words[turn][i].compareTo(words[1 - turn][i]) > 0) {        // Choose the current words[turn][i].      } else if (words[turn][i + 1] != null) {        // Choose the next words[turn][i + 1].        ++i;      } else {        // Game over. If it's Bob's turn, Alice wins, and vice versa.        return turn == 1;      }  }}

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