c - 随机猜谜游戏卡住了

Question

我正在使用《SAMS 自学 C 21 天》一书练习 C 编程基础知识。

在输入和运行部分之一，他们有查找数字(或猜测数字)程序，我输入并运行它，但是控制台上的程序卡住了，显示以下内容:

获取随机数

我等了一段时间，但没有任何反应，即使按下一些键也没有任何反应。

我还不熟悉 srand()、time() 和 rand() 例程，所以我不知道如何修复它并使其正常运行。

下面是代码:

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define NO 0
#define YES 1

int main (void)
{
    int guess_value = -1;
    int number;
    int nbr_of_guesses;
    int done = NO;


    printf("\nGetting a random number\n");

    /*use the time to seed the random number generator*/

    srand( (unsigned) time(NULL)); 
    number = rand();


    nbr_of_guesses = 0;

    while (done == NO);
    {
        printf("\nPick a number between 0 and %d>", RAND_MAX);
        scanf("%d", &guess_value); /*get a number*/

        nbr_of_guesses++;

        if (number == guess_value)
        {
            done = YES;
        }
        else
            if (number < guess_value)
            {
                printf("\nYou guessed high!");
            }
            else
            {
                printf("\nYou guessed low!");
            }

    }

    printf("\nCongratulations! you guessed right in %d Guesses!", nbr_of_guesses);
    printf("\n\nThe number was %d", number);

    return 0;
}

Answer 1

我发现有 2 个问题。

while 上有一个分号导致程序挂起。

没有什么可以确保在您读取猜测之前刷新输出缓冲区。

我已添加注释来指示代码更改。

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define NO 0
#define YES 1

int main (void)
{
    int guess_value = -1;
    int number;
    int nbr_of_guesses;
    int done = NO;


    printf("\nGetting a random number\n");

    /*use the time to seed the random number generator*/

    srand( (unsigned) time(NULL)); 
    number = rand();


    nbr_of_guesses = 0;

    while (done == NO)   // Removed the ;
    {
        printf("\nPick a number between 0 and %d>", RAND_MAX);
        fflush(stdout);  // stdout is line buffered, and since there is no \n in the printf we need an explicit call to fflush,
        scanf("%d", &guess_value); /*get a number*/

        nbr_of_guesses++;

        if (number == guess_value)
        {
            done = YES;
        }
        else
            if (number < guess_value)
            {
                printf("\nYou guessed high!");
            }
            else
            {
                printf("\nYou guessed low!");
            }

    }

    printf("\nCongratulations! you guessed right in %d Guesses!", nbr_of_guesses);
    printf("\n\nThe number was %d", number);

    return 0;
}