Cs50 Tideman Solution -

// Allocate memory for voters and candidates *voters_prefs = malloc(*voters * sizeof(voter_t)); candidate_t *candidates_list = malloc(*candidates * sizeof(candidate_t));

// Function to read input void read_input(int *voters, int *candidates, voter_t **voters_prefs) { // Read in the number of voters and candidates scanf("%d %d", voters, candidates);

3 3 1 2 3 1 3 2 2 1 3 This input represents an election with 3 voters and 3 candidates. The output of the program should be:

// Structure to represent a voter typedef struct voter { int *preferences; } voter_t; Cs50 Tideman Solution

printf("The winner is: %d\n", winner);

eliminate_candidate(candidates_list, candidates, eliminated);

// Count first-place votes for (int i = 0; i < voters; i++) { for (int j = 0; j < candidates; j++) { if (j == 0) { candidates_list[voters_prefs[i].preferences[j] - 1].votes++; } } } } // Allocate memory for voters and candidates *voters_prefs

Tideman is a voting system implemented in the CS50 course, where voters rank candidates in order of preference. The goal of the Tideman solution is to determine the winner of an election based on the ranked ballots. In this report, we will outline the problem, provide a high-level overview of the solution, and walk through the implementation.

// Read in voter preferences for (int i = 0; i < *voters; i++) { (*voters_prefs)[i].preferences = malloc(*candidates * sizeof(int)); for (int j = 0; j < *candidates; j++) { scanf("%d", &(*voters_prefs)[i].preferences[j]); } } }

count_first_place_votes(voters_prefs, voters, candidates_list, candidates); In this report, we will outline the problem,

The implementation involves the following functions: #include <stdio.h> #include <stdlib.h>

// Function to check for winner int check_for_winner(candidate_t *candidates_list, int candidates) { // Check if any candidate has more than half of the first-place votes for (int i = 0; i < candidates; i++) { if (candidates_list[i].votes > candidates / 2) { return i + 1; } } return -1; }

The CS50 Tideman solution implements a voting system that determines the winner of an election based on ranked ballots. The solution involves reading input, initializing data structures, counting first-place votes, checking for a winner, eliminating candidates, and recounting votes. The implementation includes test cases to verify its correctness.

int winner = check_for_winner(candidates_list, candidates); while (winner == -1) { // Eliminate candidate with fewest votes int eliminated = -1; int min_votes = voters + 1; for (int i = 0; i < candidates; i++) { if (candidates_list[i].votes < min_votes) { min_votes = candidates_list[i].votes; eliminated = candidates_list[i].id; } }

int main() { int voters, candidates; voter_t *voters_prefs; read_input(&voters, &candidates, &voters_prefs);