如何使用rand函数填充数组？

I want to fill a matrix starting from the center. After this, I must supply positions with the rand () function, the stop condition being to find a position where the neighbor has a value of 1 allocated. This must be done until you reach the boundary of the matrix, that is, a for x or y when they assume position 0 or (size-1)

我想从中心开始填充矩阵。在此之后，我必须使用rand（）函数提供位置，停止条件是找到一个位置，其中邻居的值为1。必须这样做，直到到达矩阵的边界，即当它们假定位置0或（大小-1）时为x或y

x = y = (size + 1) / 2;
   matrix[x][y]=1;                   //default of the matrix
    do{
       x1=rand() %(size-1);          //random position in x
       y1=rand() %(size-1);          // random position in y
       matrix[x1][y1]=1;             //declare the value in the position obtained
    }while((matrix[x1-1][y1  ]==0)||
           (matrix[x1+1][y1  ]==0)||
           (matrix[x1  ][y1-1]==0)|| 
           (matrix[x1  ][y1+1]==0)||
           (x1==x)||(y1==y));

My main question is whether my conditional is true, and how could I stop this bond when I reach the boundary of the matrix.

我的主要问题是我的条件是否正确，当我到达矩阵的边界时，我怎么能阻止这种联系。

1 个解决方案

#1

To move outward from the center of the matrix, select a square around the center and iterate through the elements in that square. Here is an example which works with a matrix with an odd size. You can add additional conditions for setting the value based on the value of the neighbors.

要从矩阵的中心向外移动，请选择围绕中心的正方形并迭代该正方形中的元素。这是一个使用奇数大小的矩阵的例子。您可以根据邻居的值添加其他条件来设置值。

int main(void)
{
    srand((unsigned)time(NULL));
    int size = 21;
    int **matrix = malloc(size * sizeof(int*));
    for(int i = 0; i < size; i++)
        matrix[i] = malloc(size * sizeof(int));

    for(int i = 0; i < size; i++)
        for(int j = 0; j < size; j++)
            matrix[i][j] = 0;

    int center = size / 2 + 1;
    matrix[center][center] = 1;
    for(int range = 1; range < size / 2; range++)
    {
        for(int i = center - range; i < center + range; i++)
            for(int j = center - range; j < center + range; j++)
            {
                if(
                    (i == (center - range))||
                    (j == (center - range))||
                    (i == (center + range - 1))||
                    (j == (center + range - 1))
                    )
                    if(rand() % 2)
                        matrix[i][j] = 1;
            }
    }

    for(int i = 0; i < size; i++)
    {
        for(int j = 0; j < size; j++)
            printf("%d", matrix[i][j]);
        printf("\n");
    }

    return 0;
}