将函数调用中的多维数组分配给变量

Question

大家好，我有一个问题

如何将多维数组从函数传递到主函数，然后我们想从那里将​​它传递给另一个函数。

float array2[][3] = get_sizes(numbers);

编译器说上面的字符串是一个错误，因为 getizes 是一个无效的初始化程序。 有人能告诉我们我们做错了什么吗？ 提前谢谢你。

编辑

int main() 

{  

float anzahl = get_number();

if(feof(stdin))
{
return 0;
}
int anzahl2 = anzahl;
float array2[][3] = get_sizes(anzahl);
if (feof(stdin)) 
{
  return 0;
}
triangulation(array2, anzahl2);  

return 0;
}

int get_number(void)
{
printf("Please enter the number of triangles to check: ");
int anzahl = 0;
char check = 0;
int ret = 0;
while(!(ret == 2 && check == '\n'))
{
ret = scanf("%d%c", &anzahl, &check);
if (feof(stdin))
{
  return 0;
}
if (check != '\n')
{
printf("[ERR] Invalid number of triangles.\n");
printf("Please enter the number of triangles to check: ");
my_flush();  
}
if((check == '\n' && anzahl > UCHAR_MAX) || (check == '\n' && anzahl <= 0))
{
printf("[ERR] Invalid number of triangles.\n");
printf("Please enter the number of triangles to check: ");
ret = 3;
}
}
return anzahl;

void my_flush(void) 
{
while(getchar() != '\n')
{
}
}

int vgl(const void *a, const void *b)
{
int aa, bb;
aa = *(int *)a;
bb = *(int *)b; 
return (aa - bb);   

float get_sizes(int anzahl)
{
float array [3] = {0,0,0};
float array2[100][3];
while(anzahl>0)
{
char check = 0;
int ret = 0;    
while(!(ret == 2 && check == '\n'))
{
  printf("Please enter the first number of the triplet: ");
  ret = scanf("%f%c",&array[0], &check);
  if (feof(stdin))
  {
    return 0;
  }
  if (check != '\n')
  {
    printf("[ERR] Invalid number of triangles.\n");
    my_flush();  
   }
   if((check == '\n' && array[0] <= 0.0)|| (check == '\n' && array[0] >= 
   FLT_MAX))
   {
    printf("[ERR] Invalid number of triangles.\n");
    ret = 3;
   }
   }
   check = 0;
   ret = 0;
   while(!(ret == 2 && check == '\n'))
   {
  printf("Please enter the second number of the triplet: ");
  ret = scanf("%f%c",&array[1], &check);
  if (feof(stdin))
  {
    return 0;
  }
  if (check != '\n')
  {
  printf("[ERR] Invalid number of triangles.\n");
  my_flush();  
  }
  if((check == '\n' && array[0] <= 0.0)|| (check == '\n' && array[0] >= 
  FLT_MAX))
  {
  printf("[ERR] Invalid number of triangles.\n");
  ret = 3;
  }
  }
  check = 0;
  ret = 0;
  while(!(ret == 2 && check == '\n'))
  {
  printf("Please enter the third number of the triplet: ");
  ret = scanf("%f%c",&array[2], &check);
  if (feof(stdin))
  {
    return 0;
  }
  if (check != '\n')
  {
  printf("[ERR] Invalid number of triangles.\n");
  my_flush();  
  }
  if((check == '\n' && array[0] <= 0.0)|| (check == '\n' && array[0] >= 
  FLT_MAX))
  {
  printf("[ERR] Invalid number of triangles.\n");
  ret = 3;
  }
  }
  qsort(array, 3, sizeof(array[3]), vgl);
  array2[anzahl][0]=array[0];
  array2[anzahl][1]=array[1];
  array2[anzahl][2]=array[2];
  anzahl--;
  } 
  return array2;

  float triangulation(float array2[100][3], int anzahl2)
  {
  int number = 1;
  while(anzahl2>0)
  {
  if(array2[anzahl2][0] == 1 && array2[anzahl2][1] == 1 && array2[anzahl2]
  [2] == 2)
  {
  printf("Tripelt %d (a=%f, b=%f, c=%f)is NO triangle.\n", number, 
  array2[anzahl2][0], array2[anzahl2][1], array2[anzahl2][2]);
  }
  else
  {
  printf("Tripelt %d (a=%f, b=%f, c=%f)is a triangle.\n", number, 
  array2[anzahl2][0], array2[anzahl2][1], array2[anzahl2][2]);
  if(array2[anzahl2][0] == array2[anzahl2][1] && array2[anzahl2][0] == 
  array2[anzahl2][2] && array2[anzahl2][1]== array2[anzahl2][2])
  {
  printf("It is an equilateral triangle.\n");
  printf("It is a isosceles triangle.\n");
  }
  else if(array2[anzahl2][0] == array2[anzahl2][1] || array2[anzahl2][0] == 
  array2[anzahl2][2] || array2[anzahl2][1]== array2[anzahl2][2])
  {
    printf("It is a isosceles triangle.\n");
  }
  else if(((array2[anzahl2][0])*(array2[anzahl2][0])) + ((array2[anzahl2]
  [1])*(array2[anzahl2][1])) == ((array2[anzahl2][2])*(array2[anzahl2][2])))
  {
    printf("It is a right triangle.\n");
  }
  } 
   anzahl2--;
   number++;
   }        
   }

这是我很长的整个代码

我们不能使用全局变量

Answer 1

这是一个演示程序，展示了一般情况下如何完成。

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

#define N   3

float ( * get_sizes( size_t n ) )[N]
{
    float ( *a )[N] = malloc( n * sizeof( float[N] ) );

    for ( size_t i = 0; i < n; i++ )
    {
        for ( size_t j = 0; j < N; j++ )
        {
            a[i][j] = i * N + j;
        }
    }

    return a;
}

void display( float( *a )[N], size_t n )
{
    for ( size_t i = 0; i < n; i++ )
    {
        for ( size_t j = 0; j < N; j++ )
        {
            printf( "%4.1f ", a[i][j] );
        }
        putchar( '\n' );
    }
}

int main(void) 
{
    size_t n = 4;
    float ( *a )[N] = get_sizes( 4 );

    display( a, n );

    free( a );

    return 0;
}

程序输出是

 0.0  1.0  2.0 
 3.0  4.0  5.0 
 6.0  7.0  8.0 
 9.0 10.0 11.0 

即需要动态分配数组。

Answer 2

这个简单的代码告诉你如何将一个二维数组发送给一个函数。函数func1 检索float a 中由int x 和int y 指向的值。对于两个以上的维度也应该这样做。

#include <stdio.h>

float func1(float *,int x, int y,int mx, int my);

float func1(float * a,int x, int y,int mx, int my)
{
    if (x>=mx)
        return 0;

    if (y>=my)
        return 0;

    return a[x*my+y];
}

int main(void)
{
#define _MX 4
#define _MY 3
    int x, y;

    float a[_MY][_MX] = {
        {0.0,0.1,0.2,0.3},
        {1.0,1.1,1.2,1.3},
        {2.0,2.1,2.2,2.3}
    };

    for(x=0;x<_MX;x++) {
        for(y=0;y<_MY;y++){
            // With cast
            printf("x =%2d y =%2d => v = %f\n",x,y,func1((float *)a,x,y,_MX,_MY));
        }
    }

    puts("---------------------------------");

    for(x=0;x<_MX;x++) {
        for(y=0;y<_MY;y++){
            // Without cast
            printf("x =%2d y =%2d => v = %f\n",x,y,func1(a[0],x,y,_MX,_MY));
        }
    }

    return 0;
}