c语言 - 我不知道错误是什么

Question

我在C中编写了此代码，以读取数字数组，然后将它们写入屏幕，但是对于n（例如n = 6）的某些值，它会出现错误。怎么了？

     #include <stdio.h>
#include <stdlib.h>
int n;
void read(int *a)
{
    int i;
    for(i=0;i<n;i++) scanf("%d",a+i);
}
void write(int *a)
{
    int i;
    for(i=0;i<n;i++) printf("%d",*(a+i));
}
int main()
{
    int *a;
    printf("n=");
    scanf("%d",&n);
    a=(int *)malloc(n*sizeof(int));
    read(&a);
    write(&a);
    return 0;
}

Answer 1

您正在错误地调用read()，而write()不正确 - 您不应该接受已经指向的地址。

更改：

read(&a);
write(&a);

to：

read(a);
write(a);

请注意，将来，您应该始终启用编译器警告并注意它们 - 如果启用编译器警告，此错误将很明显：

<stdin>:21:10: warning: incompatible pointer types passing 'int **' to parameter of type 'int *'; remove & [-Wincompatible-pointer-types]
    read(&a);
         ^~
<stdin>:4:16: note: passing argument to parameter 'a' here
void read(int *a)
               ^
<stdin>:22:11: warning: incompatible pointer types passing 'int **' to parameter of type 'int *'; remove & [-Wincompatible-pointer-types]
    write(&a);
          ^~
<stdin>:9:17: note: passing argument to parameter 'a' here
void write(int *a)
                ^
2 warnings generated.

Answer 2

看一下：

#include <stdio.h>
int n;
void read(int *a)
{
    int i;
    for (i = 0; i < n; i++)
    {
        scanf("%d", (a + i));
        // don't forget to consume the rest of line until ENTER
        scanf("%*[^n]");   // consume all caracters until the newline
        scanf("%*c");       // consume the newline
    }
}
void write(int *a)
{
    int i;
    for (i = 0; i<n; i++) printf("%d", *(a + i));
}
int main(int argc, char *argv[])
{
    int *a;
    printf("n= ");
    scanf("%d", &n);
    // don't forget to consume the rest of line until ENTER
    scanf("%*[^n]");   // consume all caracters until the newline
    scanf("%*c");       // consume the newline
    a = (int *)malloc(n*sizeof(int));
    // this is a FATAL ERROR !
    //read(&a);
    //write(&a);
    read(a);
    write(a);
    printf("n");
    // don't forget to release memory allocated with 'malloc'
    free(a);
    return(0);
}

我想要什么？如果是这样，请享受。