c - C中指向二维数组的指针

Question

我正在尝试用 C 编写数独求解器。我尝试制作一个函数来解决数独问题，然后返回网格。

void solve(int *grid){
    //solve sudoku
}

int main(){
    int[][] grid = {
        {5,3,0,0,7,0,0,0,0},
        {6,0,0,1,9,5,0,0,0},
        {0,9,8,0,0,0,0,6,0},
        {8,0,0,0,6,0,0,0,3},
        {4,0,0,8,0,3,0,0,1},
        {7,0,0,0,2,0,0,0,6},
        {0,6,0,0,0,0,2,8,0},
        {0,0,0,4,1,9,0,0,5},
        {0,0,0,0,8,0,0,7,9}
    };
solve(&grid);
}

这似乎行不通。它需要一个指针，因为它应该编辑数组而不是副本这是为什么？

Answer 1

首先声明一个数组

int[][] grid = {
    {5,3,0,0,7,0,0,0,0},
    {6,0,0,1,9,5,0,0,0},
    {0,9,8,0,0,0,0,6,0},
    {8,0,0,0,6,0,0,0,3},
    {4,0,0,8,0,3,0,0,1},
    {7,0,0,0,2,0,0,0,6},
    {0,6,0,0,0,0,2,8,0},
    {0,0,0,4,1,9,0,0,5},
    {0,0,0,0,8,0,0,7,9}
};

错了。您必须在标识符后使用方括号，并至少指定内部维度中的元素数。

#define N 9

//...
int grid[][N]  = {
    {5,3,0,0,7,0,0,0,0},
    {6,0,0,1,9,5,0,0,0},
    {0,9,8,0,0,0,0,6,0},
    {8,0,0,0,6,0,0,0,3},
    {4,0,0,8,0,3,0,0,1},
    {7,0,0,0,2,0,0,0,6},
    {0,6,0,0,0,0,2,8,0},
    {0,0,0,4,1,9,0,0,5},
    {0,0,0,0,8,0,0,7,9}
};

如果你想将数组传递给一个函数，那么这个函数可以这样声明

void solve( int ( *grid )[N], size_t n );

并称呼为

solve( grid, N );

请注意，数组没有复制赋值运算符，您不能使用指针分配数组标识符。