使用指针到整数的二维矩阵和。

#include<stdio.h>
int main()
{
    int (*p)[3],i,j;
    int (*q)[3];
    int (*r)[3];
    printf("Enter 6 integers of first matrix:\n");
    for(i=0;i<2;i++)
        for(j=0;j<3;j++)
            scanf("%d",*(p+i)+j);
    printf("The matrix you have entered is:\n");
    for(i=0;i<2;i++)
    {
        for(j=0;j<3;j++)
    {
        printf(" %d ", *(*(p+i)+j));
    }
    printf("\n");
}
printf("Enter 6 integers of second matrix:\n");
for(i=0;i<2;i++)
    for(j=0;j<3;j++)
        scanf("%d",*(q+i)+j);

printf("The matrix you have entered is:\n");
for(i=0;i<2;i++)
{
    for(j=0;j<3;j++)
    {
        printf(" %d ", *(*(q+i)+j));
    }
    printf("\n");
}
for(i=0;i<2;i++)
{
    for(j=0;j<3;j++)
    {
        *(*(r+i)+j)=*(*(p+i)+j) + *(*(q+i)+j);
    }
}
printf("The summation matrix is:\n");
for(i=0;i<2;i++)
{
    for(j=0;j<3;j++)
    {
        printf(" %d ", *(*(r+i)+j));
    }
    printf("\n");
}


}

In this program I have declared 3 pointers to an array of 3 integers. when I execute, the first matrix works fine and displayed. However, when I enter integers for the second matrix it crashes. I tried a lot but it fails.

在这个程序中，我声明了3个指向3个整数数组的指针。当我执行时，第一个矩阵工作良好并显示出来。但是，当我为第二个矩阵输入整数时，它会崩溃。我试了很多，但是失败了。

1 个解决方案

#1

As you say you have a pointer , pointer should point to some memory location before writing something to it. In your case the pointer doesn't point to any valid memory location and hence the crash.

当你说你有一个指针时，指针应该在写东西之前指向某个内存位置。在这种情况下，指针不会指向任何有效的内存位置，从而导致崩溃。

If you want a 2*3 matrix then you should be having

如果你想要一个2*3矩阵那么你应该有

char *p[2];

p[0] =  malloc(sizeof(int) *3);

Then

然后

p[i][j] is valid.

p[我][j]是有效的。

Similarly you should allocate memory for each pointers individually.

同样，应该为每个指针单独分配内存。

#1