c - 我如何在不使用 stdlib.h 的情况下执行此代码

Question

我不断收到有关 malloc 的错误消息，我正在尝试了解如何在不使用 header 中的 stdlib.h 的情况下使此代码正常工作。只是 stdio.h，这可能吗？如何实现？因为我完全糊涂了

#include <stdio.h>

void allocate(int* score_array, const int input)
{
    int iter;

    for(iter = 1;iter <= 11;++iter)
    {
        if( (input < iter*10) && (input >= (iter-1)*10 ) )
        {
            ++(score_array[iter-1]);
        }
    }
}

void printf_star(const int len)
{
    int iter;

    for(iter = 0;iter < len;++iter)
    {
        printf("*");
    }

    printf("\n");
}

int main()
{
    int iter, size, temp;
    int* buffer;
    int score_array[11];

    for(iter = 0;iter < 11;++iter)
    {
        score_array[iter] = 0;
    }

    printf("How many grades will you be entering?\n");
    printf("Enter a number between 1 and 100: ");
    scanf("%d", &size);

    buffer = (int*)malloc(size*sizeof(int));

    for(iter = 1;iter <= size;++iter )
    {
        printf("Getting grade %d. You have %d grade(s) left to enter\n", iter, size-iter+1);
        printf("Enter a number between 0 and 100: ");
        scanf("%d",&temp);

        if( (temp>=0) && (temp <= 100) )
        {
            buffer[iter-1] = temp;
        }
        else
        {
            do
            {
                printf("Invalid Value!\n");
                printf("Getting grade %d. You have %d grade(s) left to enter\n", iter, size-iter+1);
                printf("Enter a number between 0 and 100: ");
                scanf("%d",&temp);
            }
            while( (temp < 0) || (temp > 100) );
        }
    }

    for(iter = 1;iter <= size;++iter)
    {
        allocate(score_array, buffer[iter-1]);
    }

    for(iter = 0;iter < 11;++iter)
    {
        printf_star(score_array[iter]);
    }

    return 0;
}

我一直收到这个错误:

hw08.c: In function ‘main’:
hw08.c:56: warning: incompatible implicit declaration of built-in function ‘malloc’

Answer 1

这只是一个警告，不是真正的错误，所以程序仍然可以编译。

要消除警告，您可以在文件中声明 malloc:

#include <stdio.h>
extern void * malloc(unsigned long);

您也可以只包含 stdlib.h，除非您有重大理由不这样做。