36:有效的数独

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huangge1199@hotmail.com 2021-04-20 23:23:05 +08:00
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//请你判断一个 9x9 的数独是否有效只需要 根据以下规则 验证已经填入的数字是否有效即可
//
//
// 数字 1-9 在每一行只能出现一次
// 数字 1-9 在每一列只能出现一次
// 数字 1-9 在每一个以粗实线分隔的 3x3 宫内只能出现一次请参考示例图
//
//
// 数独部分空格内已填入了数字空白格用 '.' 表示
//
// 注意
//
//
// 一个有效的数独部分已被填充不一定是可解的
// 只需要根据以上规则验证已经填入的数字是否有效即可
//
//
//
//
// 示例 1
//
//
//输入board =
//[["5","3",".",".","7",".",".",".","."]
//,["6",".",".","1","9","5",".",".","."]
//,[".","9","8",".",".",".",".","6","."]
//,["8",".",".",".","6",".",".",".","3"]
//,["4",".",".","8",".","3",".",".","1"]
//,["7",".",".",".","2",".",".",".","6"]
//,[".","6",".",".",".",".","2","8","."]
//,[".",".",".","4","1","9",".",".","5"]
//,[".",".",".",".","8",".",".","7","9"]]
//输出true
//
//
// 示例 2
//
//
//输入board =
//[["8","3",".",".","7",".",".",".","."]
//,["6",".",".","1","9","5",".",".","."]
//,[".","9","8",".",".",".",".","6","."]
//,["8",".",".",".","6",".",".",".","3"]
//,["4",".",".","8",".","3",".",".","1"]
//,["7",".",".",".","2",".",".",".","6"]
//,[".","6",".",".",".",".","2","8","."]
//,[".",".",".","4","1","9",".",".","5"]
//,[".",".",".",".","8",".",".","7","9"]]
//输出false
//解释除了第一行的第一个数字从 5 改为 8 以外空格内其他数字均与 示例1 相同 但由于位于左上角的 3x3 宫内有两个 8 存在, 因此这个数独是无
//效的
//
//
//
// 提示
//
//
// board.length == 9
// board[i].length == 9
// board[i][j] 是一位数字或者 '.'
//
// Related Topics 哈希表
// 👍 504 👎 0
package leetcode.editor.cn;
import java.util.HashMap;
import java.util.Map;
//36:有效的数独
public class ValidSudoku {
public static void main(String[] args) {
//测试代码
Solution solution = new ValidSudoku().new Solution();
System.out.println(solution.isValidSudoku(new char[][]{
{'5', '3', '.', '.', '7', '.', '.', '.', '.'},
{'6', '.', '.', '1', '9', '5', '.', '.', '.'},
{'.', '9', '8', '.', '.', '.', '.', '6', '.'},
{'8', '.', '.', '.', '6', '.', '.', '.', '3'},
{'4', '.', '.', '8', '.', '3', '.', '.', '1'},
{'7', '.', '.', '.', '2', '.', '.', '.', '6'},
{'.', '6', '.', '.', '.', '.', '2', '8', '.'},
{'.', '.', '.', '4', '1', '9', '.', '.', '5'},
{'.', '.', '.', '.', '8', '.', '.', '7', '9'}
}));
}
//力扣代码
//leetcode submit region begin(Prohibit modification and deletion)
class Solution {
public boolean isValidSudoku(char[][] board) {
Map<Integer, Integer>[] row = new HashMap[9];
Map<Integer, Integer>[] column = new HashMap[9];
Map<Integer, Integer>[] other = new HashMap[9];
for (int i = 0; i < 9; i++) {
row[i] = new HashMap<>();
column[i] = new HashMap<>();
other[i] = new HashMap<>();
}
for (int i = 0; i < 9; i++) {
for (int j = 0; j < 9; j++) {
char ch = board[i][j];
if (ch == '.') {
continue;
}
int num = ch - '0';
int otherIndex = (i / 3) * 3 + j / 3;
if (row[i].containsKey(num)) {
row[i].put(num, row[i].get(num) + 1);
} else {
row[i].put(num, 1);
}
if (column[j].containsKey(num)) {
column[j].put(num, column[j].get(num) + 1);
} else {
column[j].put(num, 1);
}
if (other[otherIndex].containsKey(num)) {
other[otherIndex].put(num, other[otherIndex].get(num) + 1);
} else {
other[otherIndex].put(num, 1);
}
if (row[i].get(num) > 1 || column[j].get(num) > 1 || other[otherIndex].get(num) > 1) {
return false;
}
}
}
return true;
}
}
//leetcode submit region end(Prohibit modification and deletion)
}

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<p>请你判断一个 <code>9x9</code> 的数独是否有效。只需要<strong> 根据以下规则</strong> ,验证已经填入的数字是否有效即可。</p>
<ol>
<li>数字 <code>1-9</code> 在每一行只能出现一次。</li>
<li>数字 <code>1-9</code> 在每一列只能出现一次。</li>
<li>数字 <code>1-9</code> 在每一个以粗实线分隔的 <code>3x3</code> 宫内只能出现一次。(请参考示例图)</li>
</ol>
<p>数独部分空格内已填入了数字,空白格用 <code>'.'</code> 表示。</p>
<p><strong>注意:</strong></p>
<ul>
<li>一个有效的数独(部分已被填充)不一定是可解的。</li>
<li>只需要根据以上规则,验证已经填入的数字是否有效即可。</li>
</ul>
<p> </p>
<p><strong>示例 1</strong></p>
<img src="https://assets.leetcode-cn.com/aliyun-lc-upload/uploads/2021/04/12/250px-sudoku-by-l2g-20050714svg.png" style="height:250px; width:250px" />
<pre>
<strong>输入:</strong>board =
[["5","3",".",".","7",".",".",".","."]
,["6",".",".","1","9","5",".",".","."]
,[".","9","8",".",".",".",".","6","."]
,["8",".",".",".","6",".",".",".","3"]
,["4",".",".","8",".","3",".",".","1"]
,["7",".",".",".","2",".",".",".","6"]
,[".","6",".",".",".",".","2","8","."]
,[".",".",".","4","1","9",".",".","5"]
,[".",".",".",".","8",".",".","7","9"]]
<strong>输出:</strong>true
</pre>
<p><strong>示例 2</strong></p>
<pre>
<strong>输入:</strong>board =
[["8","3",".",".","7",".",".",".","."]
,["6",".",".","1","9","5",".",".","."]
,[".","9","8",".",".",".",".","6","."]
,["8",".",".",".","6",".",".",".","3"]
,["4",".",".","8",".","3",".",".","1"]
,["7",".",".",".","2",".",".",".","6"]
,[".","6",".",".",".",".","2","8","."]
,[".",".",".","4","1","9",".",".","5"]
,[".",".",".",".","8",".",".","7","9"]]
<strong>输出:</strong>false
<strong>解释:</strong>除了第一行的第一个数字从<strong> 5</strong> 改为 <strong>8 </strong>以外,空格内其他数字均与 示例1 相同。 但由于位于左上角的 3x3 宫内有两个 8 存在, 因此这个数独是无效的。</pre>
<p> </p>
<p><strong>提示:</strong></p>
<ul>
<li><code>board.length == 9</code></li>
<li><code>board[i].length == 9</code></li>
<li><code>board[i][j]</code> 是一位数字或者 <code>'.'</code></li>
</ul>
<div><div>Related Topics</div><div><li>哈希表</li></div></div>\n<div><li>👍 504</li><li>👎 0</li></div>