LeetCode/com/zerroi/leetcode/Three16/IsValidSudoku.java

package com.zerroi.leetcode.Three16;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

public class IsValidSudoku {
    public static void main(String[] args) {
        System.out.println(5 / 3);
    }
}

class SolutionFirst {
    public boolean isValidSudoku(char[][] board) {
        Set<Character> set = new HashSet<>();
        for (int i = 0; i < 9; i++) {
            for (int j = 0; j < 9; j++) {
                char c = board[i][j];
                if (c != '.'&& set.contains(c)) return false;
                set.add(c);
            }
            set.clear();
        }

        Set<Character> setRow = new HashSet<>();
        for (int i = 0; i < 9; i++) {
            for (int j = 0; j < 9; j++) {
                char c = board[j][i];
                if (c != '.' && setRow.contains(c)) return false;
                setRow.add(c);
            }
            setRow.clear();
        }

        Set<Character> setBlock = new HashSet<>();
        for (int i = 0; i < 9; i++) {
            int m = i / 3;
            int n = i % 3;
            setBlock.clear();
            for (int k = m * 3; k < m * 3 + 3; k++) {
                for (int j = n * 3; j < n * 3 + 3; j++) {
                    char c = board[k][j];
                    if (c != '.' && setBlock.contains(c)) return false;
                    setBlock.add(c);
                }
            }
        }
        return true;
    }

    public boolean isValidSudoku2(char[][] board) {
        Set<Character> set = new HashSet<>();
        Map<Character, Integer> map = new HashMap<>();
        for (int i = 0; i < 9; i++) {
            for (int j = 0; j < 9; j++) {
                char c = board[i][j];
                if (c != '.'&& set.contains(c)) return false;
                map.put(c, 1);
            }
            set.clear();
        }

        Set<Character> setRow = new HashSet<>();
        for (int i = 0; i < 9; i++) {
            for (int j = 0; j < 9; j++) {
                char c = board[j][i];
                if (c != '.' && setRow.contains(c)) return false;
                setRow.add(c);
            }
            setRow.clear();
        }

        Set<Character> setBlock = new HashSet<>();
        for (int i = 0; i < 9; i++) {
            int m = i / 3;
            int n = i % 3;
            setBlock.clear();
            for (int k = m * 3; k < m * 3 + 3; k++) {
                for (int j = n * 3; j < n * 3 + 3; j++) {
                    char c = board[k][j];
                    if (c != '.' && setBlock.contains(c)) return false;
                    setBlock.add(c);
                }
            }
        }
        return true;
    }
}