p275第十章函数和指针

//varrar2d.c --使用变长数组的函数

#include <stdio.h>

#define ROWS 3

#define COLS 4

int sum2d (int rows,int cols,int ar[rows][cols]);

int main (void)

{
int i,j;
int rs=j;
int cs=10;
int junk[ROWS][COLS]={
{2,4,6,8},
{3,5,7,9},
{12,10,8,6}
};
int morejunk [ROWS][COLS+2]={
{20,30,40,50,60,70},
{5,6,7,8,9,10}
};

int varr[rs][cs];

for (i=0;i<rs;i++)

for (j=0;j<cs;j++)

 varr[i][j]=i*j+j;

 printf("3X5 array\n");

 printf("Sum of all elements= %d\n",

        sum2d(ROWS-1,COLS+2,morejunk));

        printf ("3x10 VLA\n");

        printf ("Sum of all elements = %d\n",
       sum2d(ROWS-1,COLS+2,morejunk));
       
       printf ("3x10 VLA\n");
       printf ("Sum of all elements = %d\n",
sum2d(rs,cs,varr));
return 0;

 

 } 

 //带有一个VLA参数的函数

 int sum2d (int rows,int cols,int ar[rows][cols])

 {

  int r;

  int c;

  int tot=0;

  for (r=0;r<rows;r++)

  for (c=0;c<cols;c++)

   tot += ar[r][c];

   return tot;

  }