Poj 2676 Sudoku[dfs]

Main topic:

Nine problem, also some people called Sudoku problem

A grid of 9 rows and 9 columns, subdivided into 9 3*3 sub-grids, requires that only one digit in 1~9 is used in each row, column, and sub-grid, that is, the same number is not allowed in each row, per column, or in each sub-grid.

0 is the pending position, and the others are filled in.

Required to complete the nine and output (if there are multiple results, you only need to output one of them)

If the given nine can not be filled out as required, then output the original input of the nine Gongge

Ideas:

DFS Deep Search

Char map[10][10];/* data store */
BOOL row[10][10];/* Row Existence number */
BOOL col[10][10];/* Column Existence number */
BOOL grid[10][10];/* Lattice existence number */

1 /*poj2676 Sudoku*/2#include <iostream>3#include <cstdio>4#include <cstring>5 using namespacestd;6 7 Charmap[Ten][Ten];8 BOOLrow[Ten][Ten];/*Row Existence number*/9 BOOLcol[Ten][Ten];/*column existence number*/ Ten BOOLgrid[Ten][Ten];/*Lattice existence number*/ One  A BOOLDfsintXinty) - { -     if(x = =Ten) the         return true; -     BOOLFlag =false; -     if(Map[x][y]-'0') -     { +         if(Y = =9) -Flag = DFS (x+1,1); +         Else{ AFlag = DFS (x, y+1); at         } -         if(flag) -             return true; -         Else{ -             return false; -         } in     } -     Else{ to          for(inti =1; i<=9; i++) +         { -             if(!row[x][i] &&!col[y][i] &&!grid[3* ((X1)/3) + (Y1)/3+1][i]) the             { *Map[x][y] = i+'0'; $Row[x][i] =true;Panax NotoginsengCol[y][i] =true; -grid[3* ((X1)/3) + (Y1)/3+1][i] =true; the                  +                 if(Y = =9) AFlag = DFS (x+1,1); the                 Else{ +Flag = DFS (x, y+1); -                 } $                 if(!flag) $                 { -Map[x][y] ='0'; -Row[x][i] =false; theCol[y][i] =false; -grid[3* ((X1)/3) + (Y1)/3+1][i] =false;Wuyi                  the                 } -                 Else{ Wu                     return true; -                 }         About             } $         } -     } -     return false; - } A  + voidjudge () the { -memset (Row,0,sizeof(Row)); $memset (Col,0,sizeof(col)); thememset (Grid,0,sizeof(grid)); the  the      for(inti =1; i<=9; i++) the     { -          for(intj =1; j<=9; J + +) in         { the             if(Map[i][j]! ='0') the             { Aboutrow[i][map[i][j]-'0'] =true; thecol[j][map[i][j]-'0'] =true; thegrid[3* ((I-1)/3) + (J-1)/3+1][map[i][j]-'0'] =true; the             } +         } -     } the /*for (int i = 1; i<= 9; i++)Bayi     { the For (int j = 1; j<= 9; j + +) the cout<<grid[i][j]; - printf ("\ n"); -     } the printf ("\ n");  the */     the } the  - voidSolve () the { thememset (Map,0,sizeof(map)); the      for(inti =1; i<=9; i++)94     { theGets (Map[i] +1); the     } the judge ();98Dfs1,1); About      -      for(inti =1; i<=9; i++)101Puts (Map[i] +1);102printf"\ n");103 }104  the intMain ()106 {107     intT;108 //freopen ("Test.txt", "R", stdin);109scanf"%d", &t); the GetChar ();111      while(t--) the     {113 solve (); the     } the     return 0; the}

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Poj 2676 Sudoku[dfs]