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POJ 2676 暴力深搜
添加时间:2013-8-6 点击量:Description
Sudoku is a very simple task. A square table with 9 rows and 9 columns is divided to 9 smaller squares 3x3 as shown on the Figure. In some of the cells are written decimal digits 1 to 9. The other cells are empty. The goal is to fill the empty cells with decimal digits 1 to 9, one digit per cell, in such way that in each row, in each column and in each marked 3x3 subsquare, all the digits 1 to 9 to appear. Write a program to solve a given Sudoku-task.Input
The input data will start with the number of the test cases. For each test case, 9 lines follow, corresponding to the rows of the table. On each line a string of exactly 9 decimal digits is given, corresponding to the cells in this line. If a cell is empty it is represented by 0.Output
For each test case your program should print the solution in the same format as the input data. The empty cells have to be filled according to the rules. If solutions is not unique, then the program may print any one of them.Sample Input
1
103000509
002109400
000704000
300502006
060000050
700803004
000401000
009205800
804000107Sample Output
143628579
572139468
986754231
391542786
468917352
725863914
237481695
619275843
854396127解题思路:直接暴力+深度搜刮。定义状况的时辰可能有点技能。
#include<iostream>
#include<cstring>
using namespace std;
//column[][]默示第 i列数字 j是否用过,同row[][]
//grid[][]默示第 i个9X9的块内数字 j是否用过
bool flag;
bool column[10][10],row[10][10],grid[10][10];
int map[10][10];
void dfs(int x,int y)
{
if(flag)
return ;
if(x==10)
{
flag=true;
for(int i=1;i<=9;i++)
{
for(int j=1;j<=9;j++)
cout<<map[i][j];
cout<<endl;
}
return ;
}
if(map[x][y])
{
if(y==9)
dfs(x+1,1);
else
dfs(x,y+1);
}
else
{
int n=(x-1)/33+(y-1)/3+1;
for(int i=1;i<=9;i++)
{
if(!column[y][i]&&!row[x][i]&&!grid[n][i])
{
column[y][i]=true;
row[x][i]=true;
grid[n][i]=true;
map[x][y]=i;
if(y==9)
dfs(x+1,1);
else
dfs(x,y+1);
column[y][i]=false;
row[x][i]=false;
grid[n][i]=false;
map[x][y]=0;
}
}
}
}
int main()
{
int ncase;
cin>>ncase;
while(ncase--)
{
char ch[10][10];
memset(grid,false,sizeof(grid));
memset(row,false,sizeof(grid));
memset(column,false,sizeof(column));
flag=false;
for(int i=1;i<=9;i++)
{
for(int j=1;j<=9;j++)
{
cin>>ch[i][j];
map[i][j]=ch[i][j]-0;
if(map[i][j])
{
int n=(i-1)/33+(j-1)/3+1;
row[i][map[i][j]]=true;
column[j][map[i][j]]=true;
grid[n][map[i][j]]=true;
}
}
}
dfs(1,1);
}
return 0;
}
View Code
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