#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#define SIZE 9
void printSudoku(int matrix[SIZE][SIZE]) {
    for (int i = 0; i < SIZE; i++) {
        if (i % 3 == 0) {
            printf("-------------------------\n");
        }
        for (int j = 0; j < SIZE; j++) {
            if (j % 3 == 0) {
                printf("| ");
            }
            printf("%d ", matrix[i][j]);
        }
        printf("|\n");
    }
    printf("-------------------------\n");
}
void shuffleArray(int arr[], int size) {
    for (int i = size - 1; i > 0; i--) {
        int j = rand() % (i + 1);
        int temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
    }
}
void generateIncompleteMatrix(int matrix[SIZE][SIZE]) {
    srand(time(0));
    int nums[SIZE] = { 1, 2, 3, 4, 5, 6, 7, 8, 9 };
    for (int blockRow = 0; blockRow < SIZE; blockRow += 3) {
        shuffleArray(nums, SIZE);
        int idx = 0;
        for (int i = 0; i < 3; i++) {
            int count = 3;
            while (count > 0) {
                int j = rand() % SIZE;
                if (matrix[blockRow + i][j] == 0) {
                    matrix[blockRow + i][j] = nums[idx++];
                    count--;
                }
            }
        }
    }
}
int main() {
    int matrix[SIZE][SIZE] = { 0 };
    generateIncompleteMatrix(matrix);
    printSudoku(matrix);
    return 0;
}