0

After I checked my code using check50 cs50/problems/2021/x/runoff, I received the following error messages for my bool print_winner(void) function and int find_min(void) function as follows

:( print_winner prints name when someone has a majority. print_winner did not print winner of election

:( print_winner returns true when someone has a majority. print_winner did not print winner and then return true

:( find_min returns minimum number of votes for candidate. find_min did not identify correct minimum

:( find_min ignores eliminated candidates. find_min did not identify correct minimum

Any help will be greatly appreciated!

My code is as follows:

#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 candidates_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[]) // we don't need to request for each candidates name individually because we will be inputting them directly through our cmdlibne code
{
    // 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]; //argv[0] is the name of the program so we must start populating from argv[1] = argv[0 + 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
        int j;
        for (j = 0; j < candidate_count; j++)
        {
            string name = get_string("Rank %i: ", j + 1); // it is j+1 because we want to start ranking from 1 instead of 0 so it will be 1st, 2nd, 3rd etc.

            vote(i, j, name);

            // 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 candidates_name)
{
    // TODO 1.  For loop that goes through
    for (int x = 0; x < candidate_count; x++)
    {
        if (strcmp(candidates_name, candidates[x].name) == 0)
         {
            preferences[voter][rank] = x;
            printf("%i", preferences[voter][rank]);
         return true;
    }

    }

    return false;
}

// Tabulate votes for non-eliminated candidates
void tabulate(void)
{

    for (int x = 0; x < voter_count; x++)
    {
        for (int y = 0; y < candidate_count; y++)
        {
            int candidate_index = preferences[x][y];
            if (candidates[candidate_index].eliminated == false)
            {
                candidates[candidate_index].votes++;
                break;
            }
        }
    }
    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 > (float)voter_count/2)
        {
            printf("We have a winner! %s", candidates[i].name);
            return true;
        }
    }


    return false;
}

// Return the minimum number of votes any remaining candidate has
int find_min(void)
{
    int minVote = MAX_VOTERS;
    for (int x = 0; x < candidate_count; x++) 
    {
        if(candidates[x].eliminated == false && candidates[x].votes < minVote)
        
        {
            minVote = candidates[x].votes; 
            return minVote;
        }
        
    }
    
    return 0;
}

// Return true if the election is tied between all candidates, false otherwise
bool is_tie(int min)
{
    for (int x = 0; x < candidate_count; x++) 
    {
        if (candidates[x].eliminated == false && candidates[x].votes != min)
        {
            return false;
        }
    }
    
    printf(" It's a tie!");
    return true;
}

// Eliminate the candidate (or candidates) in last place
void eliminate(int min)
{
    for (int x = 0; x < candidate_count; x++)
    {
        if (candidates[x].eliminated == false && candidates[x].votes == min) 
        {
            candidates[x].eliminated = true;
        }
    }
    return;
}
2

You return prematurely. Simply finding a vote count smaller than the max is not enough. You need to keep going until you've looked at all the candidates, and then return the smallest vote count.

// Return the minimum number of votes any remaining candidate has
int find_min(void)
{
    int minVote = MAX_VOTERS;
    for (int x = 0; x < candidate_count; x++) 
    {
        if(candidates[x].eliminated == false && candidates[x].votes < minVote)
        
        {
            minVote = candidates[x].votes; 
            return minVote; // Too soon to return
        }
        
    }
    
    return 0; // 0??? You should be returning the min count you found
}

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .