#include <stdio.h>
 
#define GRID_SIZE 9
  
void initGrid(char grid[][GRID_SIZE]);
void printGrid(char grid[][GRID_SIZE]);
 
int main(void) {
    char grid[GRID_SIZE][GRID_SIZE];
 
    initGrid(grid);
    printGrid(grid);
 
    return 0;
}
 
void initGrid(char grid[][GRID_SIZE]) {
    for (int x = 0; x < GRID_SIZE; x++)
        for (int y = 0; y < GRID_SIZE; y++)
            grid[x][y] = ' ';
    // or memset(grid, ' ', GRID_SIZE * GRID_SIZE);
}
 
void printGrid(char grid[][GRID_SIZE]) {
    for (int x = 0; x < GRID_SIZE; x++) {
        for (int y = 0; y < GRID_SIZE; y++)
            printf("[%c]", grid[x][y]);
        printf("\n");
    }
}