c - 以螺旋方式打印二维数组的元素

Question

我正在尝试以螺旋方式打印数组的元素..无法找出代码中的逻辑错误..

void spiral(int n,int m,int arr[][m])
{
    int t=0,r=m-1,b=n-1,l=0,dir=0; /* t->top b->bottom l->left r->right */
    int k,j;  
    // above parameters to manage the matrix.    

    // exit condition from loop
    while (t<=b && l<=r)
    {
        // print top row
        if (dir==0)                        
        {

            for (k=l;k<=r;k++)
            {
                printf("%d  ",arr[t][k]);

            }
            dir=1;
            t++;

        }

        // print right column
        else if (dir==1)          
        {

            for (k=t;k<=b;k++)
            {
                printf("%d   ",arr[k][r]);

            }
            dir=2;
            r--;

        }

        // print bottom row
        else if (dir==2)             
        {

            for (k=r;k>=l;k--)
            {
                printf("%d   ",arr[b][k]);

            }
            dir=3;
            b--;

        }

        // print left column
        else if (dir==3)         
        {

            for (k=b;k<=t;k--)
            {
                printf("%d   ",arr[k][l]);

            }
            dir=0;
            l++;

        }
    }
}

Answer 1

要完成任务，无需使用变量 dir并在所有步骤以相同顺序重复时检查其值。

最后一个循环的条件也有错误:k <= t应该是k >= t .

这是一个可能的工作实现:

void spiral(int n,int m,int arr[][m])
{
    int top = 0,            
        right = m - 1,      
        bottom = n - 1,     
        left = 0, 
        k;  

    while( top <= bottom  &&  left <= right )
    {
        //print top row
        for ( k = left; k <= right; k++ )
        {
            printf("%d  ",arr[top][k]);
        }
        ++top;

        //print right column
        for( k = top; k <= bottom; k++ )
        {
            printf("%d   ",arr[k][right]);
        }
        --right;

        //print bottom row
        for( k = right; k >= left; k-- )
        {
            printf("%d   ",arr[bottom][k]);
        }
        --bottom;

        //print left column
        for( k = bottom; k >= top; k-- )
        // this was wrong ^^^^^^ in OP's code
        {
            printf("%d   ",arr[k][left]);
        }
        ++left;
    }
}

实例HERE