After a while i got runoff working but when i ran it through check50 there seem to be some errors but i just can't figure out what they are
:) runoff.c exists
:) runoff compiles
:) vote returns true when given name of candidate
:) vote returns false when given name of invalid candidate
:) vote correctly sets first preference for first voter
:) vote correctly sets third preference for second voter
:) vote correctly sets all preferences for voter
:) tabulate counts votes when all candidates remain in election
:) tabulate counts votes when one candidate is eliminated
:) tabulate counts votes when multiple candidates are eliminated
:) tabulate handles multiple rounds of preferences
:) print_winner prints name when someone has a majority
:) print_winner returns true when someone has a majority
:) print_winner returns false when nobody has a majority
:) print_winner returns false when leader has exactly 50% of vote
:( find_min returns minimum number of votes for candidate
find_min did not identify correct minimum
:) find_min returns minimum when all candidates are tied
:( find_min ignores eliminated candidates
find_min did not identify correct minimum
:) is_tie returns true when election is tied
:) is_tie returns false when election is not tied
:) is_tie returns false when only some of the candidates are tied
:) is_tie detects tie after some candidates have been eliminated
:) eliminate eliminates candidate in last place
:) eliminate eliminates multiple candidates in tie for last
:) eliminate eliminates candidates after some already eliminated
code:
#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
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("\n");
}
// 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)
{
// check if candidate name matches and update preferences array to match the voter and the rank of the candidate
for (int i = 0; i < candidate_count; i++)
{
if (strcmp(candidates[i].name, name) == 0)
{
preferences[voter][rank] = i;
return true;
}
}
return false;
}
// Tabulate votes for non-eliminated candidates
void tabulate(void)
{
for (int i = 0; i < voter_count; i++)
{
int j = 0;
while (candidates[preferences[i][j]].eliminated == true)
{
j++;
}
candidates[preferences[i][j]].votes++;
}
return;
}
// Print the winner of the election, if there is one
bool print_winner(void)
{
// TODO
for (int i = 0; i < candidate_count; i++)
{
if (candidates[i].votes > voter_count / 2 + 0.5)
{
printf("%s\n", candidates[i].name);
return true;
}
}
return false;
}
// Return the minimum number of votes any remaining candidate has
int find_min(void)
{
int lowestvote = candidates[0].votes;
for (int i = 0; i < candidate_count; i++)
{
if (candidates[i].eliminated == false && candidates[i].votes < lowestvote)
{
lowestvote = candidates[i].votes;
}
return lowestvote;
}
return 0;
}
// Return true if the election is tied between all candidates, false otherwise
bool is_tie(int min)
{
//
int tiecount = 0;
int remainder = 0;
bool istie = false;
for (int i = 0; i < candidate_count; i++)
{
if (!candidates[i].eliminated)
{
remainder++;
}
if (candidates[i].votes == min)
{
tiecount++;
}
if (tiecount == remainder)
{
istie = true;
}
if (tiecount != remainder)
{
istie = false;
}
}
return istie;
}
// Eliminate the candidate (or candidates) in last place
void eliminate(int min)
{
// if the candidate is not yet eliminated and has "minVotes" then eliminated == true
for (int i = 0; i < candidate_count; i++)
{
if (candidates[i].eliminated == false && candidates[i].votes == min)
{
candidates[i].eliminated = true;
}
}
return;
}
