我现在正在做CS50课程，我现在在做习题集3。我相信我的代码是正确的，但是这门课的check50，总是显示这个错误。我用项目描述中给出的例子进行了测试，得到了正确的答案。我错过什么了吗？
这是我的代码：

#include <cs50.h>
#include <stdio.h>
#include <string.h>

// Max number of candidates
#define MAX 9

// Candidates have name and vote count
typedef struct
{
    string name;
    int votes;
}
candidate;

// Array of candidates
candidate candidates[MAX];

// Number of candidates
int candidate_count;

// Function prototypes
bool vote(string name);
void print_winner(void);

int main(int argc, string argv[])
{
    // Check for invalid usage
    if (argc < 2)
    {
        printf("Usage: plurality [candidate ...]\n");
        return 1;
    }

    // Populate array of candidates
    candidate_count = argc - 1;
    if (candidate_count > MAX)
    {
        printf("Maximum number of candidates is %i\n", MAX);
        return 2;
    }
    for (int i = 0; i < candidate_count; i++)
    {
        candidates[i].name = argv[i + 1];
        candidates[i].votes = 0;
    }

    int voter_count = get_int("Number of voters: ");

    // Loop over all voters
    for (int i = 0; i < voter_count; i++)
    {
        string name = get_string("Vote: ");

        // Check for invalid vote
        if (!vote(name))
        {
            printf("Invalid vote.\n");
        }
    }

    // Display winner of election
    print_winner();
}

// Update vote totals given a new vote
bool vote(string name)
{
    bool check = false;
    for (int j = 0; j < candidate_count; j++)
    {
        if (strcmp(candidates[j].name, name) == 0)
        {
            candidates[j].votes = candidates[j].votes + 1;
            check = true;
            break;
        }
    }
    return check;
}

// Print the winner (or winners) of the election
void print_winner(void)
{
    int count = 0;
    int equal_count = 0;
    string s;
    for (int k = 0; k < candidate_count - 1; k++)
    {
        if (candidates[k].votes > candidates[k + 1].votes)
        {
            count = candidates[k].votes;
        }
        else if (candidates[k + 1].votes > candidates[k].votes)
        {
            count = candidates[k + 1].votes;
        }
        else
        {
            equal_count = candidates[k + 1].votes;
        }
    }
    if (equal_count > count)
    {
        count = equal_count;
    }
    for (int j = 0; j < candidate_count; j++)
    {
        if (candidates[j].votes == count)
        {
            s = candidates[j].name;
            printf("%s\n", s);
        }
    }

    return;
}

我得到了描述中的确切答案：

$ ./plurality Alice Bob Charlie
Number of voters: 4
Vote: Alice
Vote: Bob
Vote: Charlie
Vote: Alice
Alice

但这是我使用check50时得到的结果

:) plurality.c exists
:) plurality compiles
:) vote returns true when given name of first candidate
:) vote returns true when given name of middle candidate
:) vote returns true when given name of last candidate
:) vote returns false when given name of invalid candidate
:) vote produces correct counts when all votes are zero
:) vote produces correct counts after some have already voted
:) vote leaves vote counts unchanged when voting for invalid candidate
:( print_winner identifies Alice as winner of election
    print_winner function did not print winner of election
:) print_winner identifies Bob as winner of election
:) print_winner identifies Charlie as winner of election
:) print_winner prints multiple winners in case of tie
:) print_winner prints all names when all candidates are tied

check50总是显示此错误。