carloscn
commented
11 months ago Analysis
static int32_t check_x_matrix(int32_t *grid, size_t grid_len, size_t grid_size, bool *res)
{
int32_t ret = 0;
UTILS_CHECK_PTR(grid);
UTILS_CHECK_PTR(res);
UTILS_CHECK_LEN(grid_len);
UTILS_CHECK_LEN(grid_size);
*res = false;
for (size_t i = 0; i < grid_size; i ++) {
int32_t *grid_line = grid + i * grid_len;
for (size_t j = 0; j < grid_len; j ++) {
if ((i == j) || (i + j == grid_size - 1)) {
if (grid_line[j] == 0) {
goto finish;
}
} else if (grid_line[j] > 0) {
goto finish;
}
}
}
*res = true;
finish:
return ret;
}
Description
A square matrix is said to be an X-Matrix if both of the following conditions hold:
All the elements in the diagonals of the matrix are non-zero. All other elements are 0. Given a 2D integer array grid of size n x n representing a square matrix, return true if grid is an X-Matrix. Otherwise, return false.
Example 1:
Input: grid = [[2,0,0,1],[0,3,1,0],[0,5,2,0],[4,0,0,2]] Output: true Explanation: Refer to the diagram above. An X-Matrix should have the green elements (diagonals) be non-zero and the red elements be 0. Thus, grid is an X-Matrix.
Example 2:
Input: grid = [[5,7,0],[0,3,1],[0,5,0]] Output: false Explanation: Refer to the diagram above. An X-Matrix should have the green elements (diagonals) be non-zero and the red elements be 0. Thus, grid is not an X-Matrix.
Constraints:
n == grid.length == grid[i].length 3 <= n <= 100 0 <= grid[i][j] <= 105