[dm_code_snippet background=”yes” background-mobile=”yes” slim=”yes” line-numbers=”yes” bg-color=”#abb8c3″ theme=”dark” language=”clike” wrapped=”yes” height=”” copy-text=”Copy Code” copy-confirmed=”Copied”]
#include <cs50.h>
#include <stdio.h>
#include <string.h>
// Max voters and candidates
#define MAX_VOTERS 100
#define MAX_CANDIDATES 9
// preferences[j] is jth preference for voter i
int preferences[MAX_VOTERS][MAX_CANDIDATES];
// Candidates have name, vote count, eliminated status
typedef struct
{
string name;
int votes;
bool eliminated;
}
candidate;
// Array of candidates
candidate candidates[MAX_CANDIDATES];
// Numbers of voters and candidates
int voter_count;
int candidate_count;
// Function prototypes
bool vote(int voter, int rank, string name);
void tabulate(void);
bool print_winner(void);
int find_min(void);
bool is_tie(int min);
void eliminate(int min);
int main(int argc, string argv[])
{
// Check for invalid usage
if (argc < 2)
{
printf(“Usage: runoff [candidate …]\n”);
return 1;
}
// Populate array of candidates
candidate_count = argc – 1;
if (candidate_count > MAX_CANDIDATES)
{
printf(“Maximum number of candidates is %i\n”, MAX_CANDIDATES);
return 2;
}
for (int i = 0; i < candidate_count; i++)
{
candidates[i].name = argv[i + 1];
candidates[i].votes = 0;
candidates[i].eliminated = false;
}
voter_count = get_int(“Number of voters: “);
if (voter_count > MAX_VOTERS)
{
printf(“Maximum number of voters is %i\n”, MAX_VOTERS);
return 3;
}
// Keep querying for votes
for (int i = 0; i < voter_count; i++)
{
// Query for each rank
for (int j = 0; j < candidate_count; j++)
{
string name = get_string(“Rank %i: “, j + 1);
// Record vote, unless it’s invalid
if (!vote(i, j, name))
{
printf(“Invalid vote.\n”);
return 4;
}
printf(“%i, %i, %s\n”, i + 1, j + 1, candidates[preferences[i][j]].name);
}
printf(“\n”);
}
printf(“complete”);
return 0;
}
/*
// Keep holding runoffs until winner exists
while (true)
{
// Calculate votes given remaining candidates
tabulate();
// Check if election has been won
bool won = print_winner();
if (won)
{
break;
}
// Eliminate last-place candidates
int min = find_min();
bool tie = is_tie(min);
// If tie, everyone wins
if (tie)
{
for (int i = 0; i < candidate_count; i++)
{
if (!candidates[i].eliminated)
{
printf(“%s\n”, candidates[i].name);
}
}
break;
}
// Eliminate anyone with minimum number of votes
eliminate(min);
// Reset vote counts back to zero
for (int i = 0; i < candidate_count; i++)
{
candidates[i].votes = 0;
}
}
return 0;
}
*/
// Record preference if vote is valid
bool vote(int voter, int rank, string name)
{
printf(“voter no (via local function taking value of voter as argument).: %i, rank selected (via local function taking value of rank as argument) %i\n”, voter + 1, rank + 1);
for (int t = 0; t < candidate_count; t++)
{
if(strcmp(name, candidates[t].name) == 0)
{
preferences[voter][rank] = t;
printf(“preference of voter no. %i for rank %i is %s\n”, voter + 1, rank + 1, candidates[t].name);
return 4;
}
}
return 0;
}
/*
// Tabulate votes for non-eliminated candidates
void tabulate(void)
{
// TODO
return;
}
// Print the winner of the election, if there is one
bool print_winner(void)
{
// TODO
return false;
}
// Return the minimum number of votes any remaining candidate has
int find_min(void)
{
// TODO
return 0;
}
// Return true if the election is tied between all candidates, false otherwise
bool is_tie(int min)
{
// TODO
return false;
}
// Eliminate the candidate (or candidates) in last place
void eliminate(int min)
{
// TODO
return;
}
*/
[/dm_code_snippet]
