c++递归解数独方法示例
#include<iostream>
using namespace std;
void init();
void function(int m);
int canplace(int row,int col,int c);
void outputresult();
int a[9][9], maxm = 0;
int main()
{
init();
function(0);
return 0;
}
void init()
{
int i, j;
for(i = 0; i < 9; i++)
{
for(j = 0; j < 9; j++)
{
cin >> a[i][j];
}
}
}
void function(int m)
{
int i, j, row, col;
if (m >= 81)
{
outputresult();
}
else
{
row = m / 9;
col = m % 9;
if(a[row][col] != 0)
{
function(m+1);
}
for(i = 1; i <= 9; i++)
{
if(canplace(row,col,i) == 1)
{
a[row][col] = i;
function(m + 1);
a[row][col] = 0;
}
}
}
}
int canplace(int row,int col,int c)
{
int i, j;
int flag = 1;
for(i = 0; i < 9; i++ )
{
if(a[row][i] == c || a[i][col] == c)
{
flag = 0;
break;
}
}
if(flag != 0)
{
for(i = (row / 3) * 3; i < (row / 3) * 3 + 3; i++)
{
for(j = (col / 3) * 3; j < (col / 3) * 3 + 3; j++)
{
if(a[i][j] == c)
{
flag = 0;
break;
}
}
if(flag == 0)
{
break;
}
}
}
return flag;
}
void outputresult()
{
int i, j;
for(i = 0; i < 9; i++)
{
if(i % 3 == 0)
{
cout << endl;
}
for(j = 0; j < 9; j++)
{
if(j % 3 == 0)
{
cout << " ";
}
cout << a[i][j] << " ";
}
cout << endl;
}
cout << endl;
}