Question

我已经完成了cs50的pset3的复数程序，但是在我的代码上运行check50时，我收到了针对print_winner函数的以下错误：

:) 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 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 function did not print both winners of election
:) print_winner prints all names when all candidates are tied

即使我的函数确实在出现平局的情况下会打印出多个获胜者（并且我在各种情况下都对其进行了多次测试），但该错误仍然持续存在，我不确定为什么。有人可以在下面检查我的代码，并详细说明代码有什么问题吗？（很抱歉，如果它太乱/效率低下，我花了一段时间来写，因为花了我一段时间才弄清楚如何打印多个获奖者）：

void print_winner(void)
{
    int j = 0;
    int max = candidates[0].votes;
    int competitor;
    int competitor2;
    string winner = candidates[0].name;

    // loop over all candidates + determine candidate with most votes (max)
    // + name candidate with most votes (winner)
    for (j = 1; j < candidate_count; j++)
    {
        competitor = candidates[j].votes;
        if (max < competitor)
        {
            max = competitor;
            winner = candidates[j].name;
        }
    }

    // loop over candidates again to determine if multiple winners + print winner/winners
    for (int f = 0; f < candidate_count; f++)
    {
        competitor2 = candidates[f].votes;
        if (max == competitor2 && candidates[f].name != winner)
        {
            for (int i = 0; i < candidate_count; i++)
            {
                printf("%s\n", candidates[i].name);
            }
            return;
        }
    }
    printf("%s\n", winner);
    return;
}

编辑：正如DinoCoderSaurus指出的那样，我的i循环是有问题的。我意识到甚至没有必要，因为我的f循环已经具有相同的功能。下面，我删除了i循环，对f循环进行了一些修改，并将printf("%s\n", winner);行移到f循环之前，因此，如果有多个获胜者，他们按正确的顺序打印：

void print_winner(void)
{
    int j = 0;
    int max = candidates[0].votes;
    int competitor;
    int competitor2;
    string winner = candidates[0].name;

    // loop over all candidates + determine candidate with most votes (max)
    // + name candidate with most votes (winner)
    for (j = 1; j < candidate_count; j++)
    {
        competitor = candidates[j].votes;
        if (max < competitor)
        {
            max = competitor;
            winner = candidates[j].name;
        }
    }

    printf("%s\n", winner);
    // loop over candidates again to determine if multiple winners + print winner/winners
    for (int f = 0; f < candidate_count; f++)
    {
        competitor2 = candidates[f].votes;
        if (max == competitor2 && candidates[f].name != winner)
        {
            printf("%s\n", candidates[f].name);
        }
    }
    return;
}

Answer 1

尝试这次选举：3位候选人：a，b，c。五位投票者：a，a，b，b，c。

预期输出是多少？程序输出什么？

问题出在SELECT ca.syear, COUNT(cc.joined),cc.joined FROM schedules AS cc JOIN schedule_assignment AS ca ON ca.idx = cc.assignment where student = 1 AND cc.joined = 1 GROUP BY ca.syear;循环中。如果发现“第二名”获胜者，将打印哪些候选人名称？

CS50 pset3多个程序为print_winner函数给出错误（未同时打印两个选举的获胜者）

1 个答案: