백준 g4 2580 스도쿠 c++

https://www.acmicpc.net/problem/2580

2580번: 스도쿠

 

풀이는 여기로 https://kyj0032.tistory.com/107

백준 g4 2239 스도쿠 c++

 

전체 코드

/*boj g4 2580 스도쿠*/
#include <iostream>
#define MAXN 105
using namespace std;

int N;
string str[10];
int board[9][9];
bool isEnd() {
    for (int i = 0; i < 9; i++) {
        for (int j = 0; j < 9; j++) {
            if (board[i][j] == 0) return false;
        }
    }
    return true;
}

bool isInHorizontal(int x, int y, int k) {
    for (int j = 0; j < 9; j++) {
        if (board[x][j] == k) return true;
    }
    return false;
}

bool isInVertical(int x, int y, int k) {
    for (int i = 0; i < 9; i++) {
        if (board[i][y] == k) return true;
    }
    return false;
}

bool isInBox(int x, int y, int k) {
    // 0 1 2 / 3 4 5 / 6 7 8
    int xCond = x / 3;
    int yCond = y / 3;

    for (int i = 3 * (x / 3); i < 3 * (x / 3) + 3; i++) {
        for (int j = 3 * (y / 3); j < 3 * (y / 3) + 3; j++) {
            if (board[i][j] == k) return true;
        }
    }
    return false;
}

void print() {
    // cout << "================\n";
    for (int i = 0; i < 9; i++) {
        for (int j = 0; j < 9; j++) {
            cout << board[i][j] << " ";
        }
        cout << "\n";
    }
}

void dfs(int x, int y) {
    // print();
    //   if () x, y가 끝이면?
    if (isEnd()) {
        print();
        exit(0);
    }
    for (int i = x; i < 9; i++) {
        for (int j = 0; j < 9; j++) {
            if (board[i][j] != 0) continue;

            for (int k = 1; k <= 9; k++) {
                if (isInHorizontal(i, j, k)) continue;
                if (isInVertical(i, j, k)) continue;
                if (isInBox(i, j, k)) continue;

                board[i][j] = k;
                dfs(i, j);

                board[i][j] = 0;
            }

            return;
        }
    }
}

int main(void) {
    ios::sync_with_stdio(0);
    cin.tie(0);
    for (int i = 0; i < 9; i++) {
        for (int j = 0; j < 9; j++) {
            cin >> board[i][j];
        }
    }
    dfs(0, 0);
}