Sudoku Solver
Write a program to solve a Sudoku puzzle by filling the empty cells.
Empty cells is indicated by the character ‘.‘
.
Assume that there would be is only one unique solution.
A Sudoku Puzzle ...
... and its solution numbers marked in red.
https://leetcode.com/problems/sudoku-solver/
Another DFS.
Test case is weaker, only 6, and the deal is solvable.
Each to a lattice first to see whether it is over or not need to fill, otherwise call the Findcandidate method to find all the numbers in the current step, and then start recursion.
Every round of recursion comes back to the default '. ' Write it back, or it will affect the next round of results.
Open a flag record is not the end, if it has been traversed to return, no need to find.
1 /**2 * @param {character[][]} board3 * @return {void} does not return anything, modify board In-place instead.4 */5 varSolvesudoku =function(board) {6 varIscomplete =false;7DFS (0, 0);8 9 functiondfs (x, y) {Ten if(iscomplete) { One return; A } - varCandidates =findcandidate (x, y); - if(x = = = 8 && y = = 8){ the if(Board[8][8] = = = '. '){ -BOARD[8][8] = candidates[0]; - } -Iscomplete =true; + return; - } + A if(Board[x][y]!== '. '){ at if(Y = = 8){ -DFS (x + 1, 0); - return; -}Else{ -DFS (x, y + 1); - return; in } - } to for(vari = 0; i < candidates.length; i++){ +Board[x][y] =Candidates[i]; - if(Y = = 8){ theDFS (x + 1, 0); *}Else{ $DFS (x, y + 1);Panax Notoginseng } - if(!iscomplete) { theBoard[x][y] = '. '; +}Else{ A return; the } + } - } $ $ functionfindcandidate (x, y) { - varSet =NewSet (); - varcandidate = []; the varCell =-1; - //RowWuyi for(i = 0; i < 9; i++){ theCell =Board[x][i]; - if(!Set.has (cell)) { Wu Set.add (cell); - } About } $ //column - for(i = 0; i < 9; i++){ -Cell =Board[i][y]; - if(!Set.has (cell)) { A Set.add (cell); + } the } - //Square $ varOffsetX = parseint (X/3) * 3; the varOffsetY = parseint (Y/3) * 3; the for(i = 0; I <= 2; i++){ the for(j = 0; J <= 2; j + +){ theCell = board[i + offsetx][j +OffsetY]; - if(!Set.has (cell)) { in Set.add (cell); the } the } About } the //Find candidate the for(i = 1; I <= 9; i++){ the if(!set.has (i + ""))){ +Candidate.push (i + "")); - } the }Bayi returncandidate; the } the};
With a UT
1 functionTest () {2 varMap = [3[' 5 ', ' 3 ', '. ', '. ', ' 7 ', '. ', '. ', '. ', '. '],4[' 6 ', '. ', '. ', ' 1 ', ' 9 ', ' 5 ', '. ', '. ', '. '],5['. ', ' 9 ', ' 8 ', '. ', '. ', '. ', '. ', ' 6 ', '. '],6[' 8 ', '. ', '. ', '. ', ' 6 ', '. ', '. ', '. ', ' 3 '],7[' 4 ', '. ', '. ', ' 8 ', '. ', ' 3 ', '. ', '. ', ' 1 '],8[' 7 ', '. ', '. ', '. ', ' 2 ', '. ', '. ', '. ', ' 6 '],9['. ', ' 6 ', '. ', '. ', '. ', '. ', ' 2 ', ' 8 ', '. '],Ten['. ', '. ', '. ', ' 4 ', ' 1 ', ' 9 ', '. ', '. ', ' 5 '], One['. ', '. ', '. ', '. ', ' 8 ', '. ', '. ', ' 7 ', ' 9 '] A ] - - Solvesudoku (map); the - for(varm = 0; M < map.length; m++){ - varline = ""; - for(varn = 0; n < map[m].length; n++){ +Line + = (Map[m][n] + ","); - } + Console.log (line); A } at}
[Leetcode] [JavaScript] Sudoku Solver