Having issues with Check 50 and the is_tie function:
:( is_tie returns false when only some of the candidates are tied
is_tie did not return false
:( is_tie detects tie after some candidates have been eliminated
is_tie did not return true
I get these errors within Check50 but i am unsure why. See my code below.
bool is_tie(int min)
{
//Create a variable that stores the amount of Candidates still in the race.
int remaining_candidates = 0;
//Loop over the candidates and find out how many candidates still are standing.
for (int i = 0; i < candidate_count; i++)
{
if (candidates[i].eliminated == false)
{
remaining_candidates++;
}
}
//Loop over the candidates a second time now to test the equation and see if a tie exists
for (int j =0; j < candidate_count; j++)
{
if ((voter_count / candidates[j].votes) == remaining_candidates)
{
printf("\nIts a Tie\n");
return true;
}
else
{
return false;
}
}
return false;
}
I understand the faults to be saying that my function returns "true" when only some candidates are tied. but I thought I had eliminated this from possibly happening in the "find-min" function and the "eliminate" function as invalid candidates would be either eliminated or ignored in this function.
if anyone could give me some insight I would most appreciate it. full source code below:
#include <cs50.h>
#include <stdio.h>
#include <string.h>
// Max voters and candidates
#define MAX_VOTERS 100
#define MAX_CANDIDATES 9
// preferences[i][j] is jth preference for voter i (i being rows and j being columns)
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("Voter %i - Rank %i: ", i + 1, j + 1);
// Record vote, unless it's invalid
if (!vote(i, j, name))
{
printf("Invalid vote.\n");
return 4;
}
}
printf("\n");
}
// Keep holding runoffs until winner exists
while (true)
{
// Calculate votes given remaining candidates
tabulate();
for (int j = 0; j < candidate_count; j++)
{
printf("candidate: %s\n votes:%d\n", candidates[j].name, candidates[j].votes);
}
// 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("Joint Victor %i: %s\n",(i+1), 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)
{
// Iterate over the number of candidates
for(int i = 0; i < candidate_count; i++)
{
//Check if any of the name entered by the user matches any of the candidates names
if (strcmp(name, candidates[i].name) == 0)
{
preferences[voter][rank] = i;
return true;
break;
}
}
return false;
}
// Tabulate votes for non-eliminated candidates
void tabulate(void)
{
// Iterate over the number of candidates to find 'true' votes
for(int i = 0; i < voter_count; i++)
{
for (int j = 0; j < candidate_count; j++)
{
if (candidates[preferences[i][j]].eliminated == false)
{
candidates[preferences[i][j]].votes++;
break;
}
}
}
return;
}
// Print the winner of the election, if there is one
bool print_winner(void)
{
for (int i = 0; i < candidate_count; i++)
{
if (candidates[i].votes > (voter_count/2))
{
printf("\nElection winner: %s\n", candidates[i].name);
return true;
}
}
return false;
}
// Return the minimum number of votes any remaining candidate has
int find_min(void)
{
int losing_candidates_count = voter_count;
string losing_candidate;
for (int i = 0; i < candidate_count; i++)
{
if (candidates[i].votes < losing_candidates_count && candidates[i].eliminated == false)
{
losing_candidates_count = candidates[i].votes;
}
}
printf("\n Lowest ranking candidate: ");
for (int i = 0; i < candidate_count; i++)
{
if (candidates[i].votes == losing_candidates_count && candidates[i].eliminated == false)
{
losing_candidate = candidates[i].name;
}
}
printf(" %s\n", losing_candidate);
return losing_candidates_count;
}
// Return true if the election is tied between all candidates, false otherwise
bool is_tie(int min)
{
//Create a variable that stores the amount of Candidates still in the race.
int remaining_candidates = 0;
//Loop over the candidates and find out how many candidates still are standing.
for (int i = 0; i < candidate_count; i++)
{
if (candidates[i].eliminated == false)
{
remaining_candidates++;
}
}
//Loop over the candidates a second time now to test the equation and see if a tie exists
for (int j =0; j < candidate_count; j++)
{
if ((voter_count / candidates[j].votes) == remaining_candidates)
{
printf("\nIts a Tie\n");
return true;
}
else
{
return false;
}
}
return false;
}
// Eliminate the candidate (or candidates) in last place
void eliminate(int min)
{
for (int i = 0; i < candidate_count; i++)
{
if (candidates[i].votes == min)
{
candidates[i].eliminated = true;
}
}
return;
}
if ((voter_count / candidates[j].votes) == remaining_candidates)
. A tie means all remaining candidates have the same number of votes. It is not a function of how many candidates are remaining, it is a simply a comparison of the number of votes each remaining candidate has accumulated.