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53 lines
1.2 KiB
C#
53 lines
1.2 KiB
C#
using System.Collections.Generic;
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public class Sudoku {
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private static readonly int FULL = (~(((~0) >> 9) << 9)) << 1;
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private static IEnumerable<(int, int)> Row(int row) {
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for (var col = 0; col < 9; col++) {
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yield return (row, col);
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}
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}
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private static IEnumerable<(int, int)> Column(int column) {
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for (var row = 0; row < 9; row++) {
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yield return (row, column);
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}
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}
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private static IEnumerable<(int, int)> Box(int k) {
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var row = 3 * (k / 3);
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var col = 3 * (k % 3);
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for (var i = 0; i < 3; i++) {
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for (var j = 0; j < 3; j++) {
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yield return (row + i, col + j);
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}
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}
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}
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private static bool Valid(int[][] board, IEnumerable<(int, int)> coordinates) {
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var encountered = 0;
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foreach (var (row, col) in coordinates) {
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if (board[row][col] == 0) {
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return false;
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} else if ((encountered & (1 << board[row][col])) != 0) {
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return false;
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}
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encountered |= 1 << board[row][col];
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}
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return encountered == FULL;
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}
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public static bool ValidateSolution(int[][] board) {
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for (var i = 0; i < 9; i++) {
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if (!Valid(board, Row(i)) || !Valid(board, Column(i)) || !Valid(board, Box(i))) {
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return false;
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}
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}
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return true;
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}
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}
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