传递“更好”的参数 1 使指针从整数而不进行强制转换

Question

这是一个相当简单的程序，它找到二维数组等级的最大元素并将其打印到屏幕上

#include <stdio.h>
const int t = 5;
int num_of_students;
int better(int grades[num_of_students][t], int num_of_students)
{
    int i, k; 
    int max = grades[0][0];
    
    for (i = 0; i < num_of_students; i++)
    {
        for (k = 0; k < t; k ++)
        {
            if (grades[i][k] > max)
            {
                max = grades[i][k];
            }
        }
    }
    return max;
}
int main(void)
{
    int i, k;
    printf("Give the number of students who took the test: ");
    scanf("%i", &num_of_students);
    int grades[num_of_students][t];

    for (i = 0; i < num_of_students; i++)
    {
        printf("Student %i\n", i+1);
        for (k = 0; k < t; k++)
       {
            printf("Give the score on test %i: ", k+1);
            scanf("%i", &grades[i][k]);
            while (grades[i][k] < 0 || grades[i][k] > 100)
            {
                printf("Not an acceptable score, try again %i: ", k+1);
                scanf("%i", &grades[i][k]);
            }
        }
    }
    int max = better(grades[num_of_students][t], num_of_students);
    printf("The best score is %i\n", max);
}

然而，当我尝试运行程序时，会弹出以下错误： test.c:47:45：警告：传递“更好”的参数 1 使指针从整数而不进行强制转换 [-Wint-conversion] test.c:6:16：注意：预期为 'int (*)[(sizetype)t]' 但参数的类型为 'int'

Answer 1

对于初学者来说，改变函数声明

int better(int grades[num_of_students][t], int num_of_students)

到

int better(int num_of_students, int grades[num_of_students][t] )

否则不清楚是在第一个参数int grades[num_of_students][t]的声明中使用了全局变量num_of_students还是第二个参数的标识符。那就是函数声明，它会让代码的读者感到困惑。

然后这样称呼它

int max = better( num_of_students, grades );

否则，您将尝试传递 int 类型的数组 grades[num_of_students][t] 中不存在的元素，而不是数组本身。