This program implements the Tideman voting system, also known as the ranked pairs method. This voting system selects a single winner from a set of candidates based on ranked preferences submitted by voters. This implementation is part of the CS50 course assignment and demonstrates advanced election algorithms.

• Preference Recording: Records voter preferences to determine how many voters prefer one candidate over another.
• Pair Addition: Identifies and records pairs of candidates where one is preferred over the other.
• Pair Sorting: Sorts pairs in descending order by the margin of victory.
• Cycle Detection: Ensures that locking pairs does not create cycles in the candidate graph.
• Winner Determination: Determines and prints the winner of the election based on the locked pairs graph.

1. Compile the Program:

   gcc -o tideman tideman.c -lcs50

2. Run the Program:

   ./tideman [candidate ...]

   Replace [candidate ...] with the names of the candidates. For example:

   ./tideman Alice Bob Charlie

3. Input Voting Data:

   After running the program, you will be prompted to enter the number of voters and their preferences for each candidate.

Suppose there are three candidates: Alice, Bob, and Charlie. To run the program with these candidates:

./tideman Alice Bob Charlie You will then be asked for the number of voters and their rankings. For example:

Number of voters: 3 Rank 1: Alice Rank 2: Bob Rank 3: Charlie ... The program will output the winner of the election based on the ranked pairs method.

• Preference Recording:

  • The record_preferences function updates the preference matrix based on voter input.

• Pair Addition:

  • The add_pairs function identifies pairs of candidates where one is preferred over the other and records the strength of the preference.

• Pair Sorting:

  • The sort_pairs function sorts the pairs in descending order by the strength of victory.

• Cycle Detection:

  • The cycle_detector function checks for cycles in the graph to prevent locking pairs that would create a cycle.

• Winner Determination:

  • The print_winner function identifies and prints the candidate with no incoming edges in the locked pairs graph.

This project is licensed under the MIT License. See the LICENSE file for details.

[Ye Yint Aung]