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Sudoku Solving algorithm

Snaksa (114)
Hi guys! I'm trying to make a Sudoku Solving program for a couple of days but I'm stuck with the steps. I google an algorithm which can help me. I found this algorithm:
1. start at the first empty cell, and put 1 in it.
2. Check the entire board, and see if there are any conflicts
3. If there are coflicts on the board, increase the number in the current cell by 1 (so change 1 to 2, 2 to 3, etc)
4. If the board is clean move, start at step one again.
5. If all nine possible numbers on a given cell cause a conflict in the board, then you set this cell back to empty, go back to the previous cell, and start again from step 3 (this is where the 'backtracking' comes in).


But maybe I don't understand it well. Can someone explain this to me? Maybe you would want to see my code. Here it is. My function for checking for conflicts is not ready yet, but I can see that there is a mistake in my solving function but I don't understand what it is :/

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    #include <iostream>
    #include <iomanip>
    #include <time.h>
    #include <cstdlib>
    #include <windows.h>
    using namespace std;
    
    class Sudoku
      {
        private:
        int board[9][9];
        int change[9][9];
        public:
        Sudoku();
        void Print_Board();  
        void Add_First_Cord();  
        void Solve();
        void Help_Solve(int i, int j);
        bool Check_Conflicts(int p, int i, int j);
      };
      
    Sudoku Game;  
      
    void setcolor(unsigned short color)                 //The function that you'll use to
    {                                                   //set the colour
        HANDLE hcon = GetStdHandle(STD_OUTPUT_HANDLE);
        SetConsoleTextAttribute(hcon,color);
    }
      
    Sudoku::Sudoku()
      {
        for(int i = 1; i <= 9; i++)
          for(int j = 1; j <= 9; j++)
            board[i][j] = 0;            
      }
      
    void Sudoku::Print_Board()
      {
        for(int i = 1; i <= 9; i++)
          {
            for(int j = 1; j <= 9; j++)
              {
                if(change[i][j] == 1) 
                  {
                    setcolor(12);
                    cout << board[i][j] << " ";
                    setcolor(7);           
                  }
                  else cout << board[i][j] << " ";  
                  if(j%3 == 0) cout << "| ";
              }
            cout << endl;
            if(i%3 == 0) cout << "------+-------+---------" << endl;
                    
          }                    
      }
      
    void Sudoku::Add_First_Cord()
      {
        board[1][1] = 5; change[1][1] = 1;
        board[1][2] = 3; change[1][2] = 1;     
        board[1][5] = 7; change[1][5] = 1;      
        board[2][1] = 6; change[2][1] = 1;  
        board[2][4] = 1; change[2][4] = 1;       
        board[2][5] = 9; change[2][5] = 1;  
        board[2][6] = 5; change[2][6] = 1; 
        board[3][2] = 9; change[3][2] = 1;      
        board[3][3] = 8; change[3][3] = 1;   
        board[3][8] = 6; change[3][8] = 1;     
        board[4][1] = 8; change[4][1] = 1;    
        board[4][5] = 6; change[4][5] = 1;    
        board[4][9] = 3; change[4][9] = 1;    
        board[5][1] = 4; change[5][1] = 1; 
        board[5][4] = 8; change[5][4] = 1;  
        board[5][6] = 3; change[5][6] = 1;  
        board[5][9] = 1; change[5][9] = 1;   
        board[6][1] = 7; change[6][1] = 1; 
        board[6][5] = 2; change[6][5] = 1;   
        board[6][9] = 6; change[6][9] = 1;  
        board[7][2] = 6; change[7][2] = 1;  
        board[7][7] = 2; change[7][7] = 1;  
        board[7][8] = 8; change[7][8] = 1;  
        board[8][4] = 4; change[8][4] = 1; 
        board[8][5] = 1; change[8][5] = 1;   
        board[8][6] = 9; change[8][6] = 1; 
        board[8][9] = 5; change[8][9] = 1;   
        board[9][5] = 8; change[9][5] = 1;  
        board[9][8] = 7; change[9][8] = 1;  
        board[9][9] = 9; change[9][9] = 1;  
      }
    
    bool Sudoku::Check_Conflicts(int p, int i, int j)
      {
        for(int k = 1; k <= 9; k++)
          if(board[i][k] == p) return false;
          
        for(int q = 1; q <= 9; q++)
          if(board[q][j] == p) return false;
        
        /*
          *00
          000
          000
        */
        if((j == 1 || j == 4 || j == 7) && (i == 1 || i == 4 || i == 7))
          {
             if(board[i][j+1] == p || board[i][j+2] == p || board[i+1][j] == p || 
                 board[i+2][j] == p || board[i+1][j+1] == p || board[i+1][j+2] == p || 
                     board[i+2][j+1] == p || board[i+2][j+2] == p)return false;     
          } 
        
        
        /*
          000
          000
          *00
        */  
        if((j == 1 || j == 4 || j == 7) && (i == 3 || i == 6 || i == 9))
          {
             if(board[i-1][j] == p || board[i-2][j] == p || board[i][j+1] == p || 
                 board[i][j+2] == p || board[i-1][j+1] == p || board[i-1][j+2] == p || 
                     board[i-2][j+1] == p || board[i-2][j+2] == p)return false;   
          }
         
        /*
          000
          *00
          000
        */            
        if((j == 1 || j == 4 || j == 7) && (i == 2 || i == 5 || i == 8))
          {
             if(board[i-1][j] == p || board[i+1][j] == p || board[i-1][j+1] == p || 
                 board[i][j+1] == p || board[i+1][j+1] == p || board[i+1][j+2] == p || 
                     board[i][j+2] == p || board[i+1][j+2] == p)return false;  
          } 
          
        
        /*
          0*0
          000
          000
        */            
        if((j == 2 || j == 5 || j == 8) && (i == 1 || i == 5 || i == 7))
          {
             if(board[i-1][j] == p || board[i+1][j] == p || board[i-1][j+1] == p || 
                 board[i][j+1] == p || board[i+1][j+1] == p || board[i+1][j+2] == p || 
                     board[i][j+2] == p || board[i+1][j+2] == p)return false;  
          }
          
        /*
          000
          0*0
          000
        */            
        if((j == 2 || j == 5 || j == 8) && (i == 2 || i == 5 || i == 8))
          {
             if(board[i-1][j] == p || board[i-1][j-1] == p || board[i-1][j+1] == p || 
                 board[i][j+1] == p || board[i][j-1] == p || board[i+1][j+1] == p || 
                     board[i][j] == p || board[i+1][j-1] == p)return false;  
          }
          
        
        /*
          000
          000
          0*0
        */            
        if((j == 2 || j == 5 || j == 8) && (i == 3 || i == 6 || i == 9))
          {
             if(board[i][j-1] == p || board[i][j+1] == p || board[i-1][j] == p || 
                 board[i-1][j+1] == p || board[i-1][j-1] == p || board[i-2][j] == p || 
                     board[i-1][j+1] == p || board[i-2][j-1] == p) return false;  
          }        
        
        return true;                          
      }
     
    void Sudoku::Help_Solve(int i, int j)
      {
        if(j <= 0) 
          {
            i = i-1;
            j = 9;
          }
        if(change[i][j] == 1) return Game.Help_Solve(i, j-1);
        for(int p = 1; p <= 9; p++)
          if(Game.Check_Conflicts(p, i, j)) 
            {
              board[i][j] = p;
              return;
            }
        return Game.Help_Solve(i, j-1);
          
      }
      
    void Sudoku::Solve()
      {                          
          for(int i = 1; i <= 9; i++)
            {
              for(int j = 1; j <= 9; j++)
                {
                  if(board[i][j] == 0 && change[i][j] == 0)
                    {
                      Game.Help_Solve(i, j);           
                    }      
                }      
            }
                          
      }
    
    
    int main()
    {
      Game.Add_First_Cord();
      Game.Solve();
      Game.Print_Board();  
        
      system("pause");
      return 0;
    }
Snaksa (114)
Here is the full Check_Conflicts(...) function:
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bool Sudoku::Check_Conflicts(int p, int i, int j)
      {
        for(int k = 1; k <= 9; k++)
          if(board[i][k] == p) return false;
          
        for(int q = 1; q <= 9; q++)
          if(board[q][j] == p) return false;
        
        /*
          *00
          000
          000
        */
        if((j == 1 || j == 4 || j == 7) && (i == 1 || i == 4 || i == 7))
          {
             if(board[i][j+1] == p || board[i][j+2] == p || board[i+1][j] == p || 
                 board[i+2][j] == p || board[i+1][j+1] == p || board[i+1][j+2] == p || 
                     board[i+2][j+1] == p || board[i+2][j+2] == p)return false;     
          } 
        
        
        /*
          000
          000
          *00
        */  
        if((j == 1 || j == 4 || j == 7) && (i == 3 || i == 6 || i == 9))
          {
             if(board[i-1][j] == p || board[i-2][j] == p || board[i][j+1] == p || 
                 board[i][j+2] == p || board[i-1][j+1] == p || board[i-1][j+2] == p || 
                     board[i-2][j+1] == p || board[i-2][j+2] == p)return false;   
          }
         
        /*
          000
          *00
          000
        */            
        if((j == 1 || j == 4 || j == 7) && (i == 2 || i == 5 || i == 8))
          {
             if(board[i-1][j] == p || board[i+1][j] == p || board[i-1][j+1] == p || 
                 board[i][j+1] == p || board[i+1][j+1] == p || board[i+1][j+2] == p || 
                     board[i][j+2] == p || board[i+1][j+2] == p)return false;  
          } 
          
        
        /*
          0*0
          000
          000
        */            
        if((j == 2 || j == 5 || j == 8) && (i == 1 || i == 5 || i == 7))
          {
             if(board[i-1][j] == p || board[i+1][j] == p || board[i-1][j+1] == p || 
                 board[i][j+1] == p || board[i+1][j+1] == p || board[i+1][j+2] == p || 
                     board[i][j+2] == p || board[i+1][j+2] == p)return false;  
          }
          
        /*
          000
          0*0
          000
        */            
        if((j == 2 || j == 5 || j == 8) && (i == 2 || i == 5 || i == 8))
          {
             if(board[i-1][j] == p || board[i-1][j-1] == p || board[i-1][j+1] == p || 
                 board[i][j+1] == p || board[i][j-1] == p || board[i+1][j+1] == p || 
                     board[i][j] == p || board[i+1][j-1] == p)return false;  
          }
          
        
        /*
          000
          000
          0*0
        */            
        if((j == 2 || j == 5 || j == 8) && (i == 3 || i == 6 || i == 9))
          {
             if(board[i][j-1] == p || board[i][j+1] == p || board[i-1][j] == p || 
                 board[i-1][j+1] == p || board[i-1][j-1] == p || board[i-2][j] == p || 
                     board[i-1][j+1] == p || board[i-2][j-1] == p) return false;  
          }  
          
        /*
          00*
          000
          000
        */            
        if((j == 3 || j == 6 || j == 9) && (i == 1 || i == 4 || i == 7))
          {
             if(board[i][j-1] == p || board[i][j-2] == p || board[i+1][j] == p || 
                 board[i+1][j-1] == p || board[i+1][j-2] == p || board[i+2][j] == p || 
                     board[i+2][j-1] == p || board[i+2][j-2] == p) return false;  
          } 
          
        /*
          000
          00*
          000
        */            
        if((j == 3 || j == 6 || j == 9) && (i == 2 || i == 5 || i == 8))
          {
             if(board[i-1][j] == p || board[i-1][j-1] == p || board[i-1][j-2] == p || 
                 board[i][j-1] == p || board[i][j-2] == p || board[i+1][j] == p || 
                     board[i+1][j-1] == p || board[i+1][j-2] == p) return false;  
          }
          
        /*
          000
          000
          00*
        */            
        if((j == 3 || j == 6 || j == 9) && (i == 3 || i == 6 || i == 9))
          {
             if(board[i][j-1] == p || board[i][j-1] == p || board[i-1][j] == p || 
                 board[i-1][j-1] == p || board[i-1][j-2] == p || board[i-2][j] == p || 
                     board[i-2][j-1] == p || board[i-2][j-2] == p) return false;  
          }      
        
        return true;                          
      }
cire (8284)
One thing to remember is that valid indices for arrays are 0 to size-1. So for a two dimensional array where the size of each dimension is 9, the maximum index for each dimension is 8.

If you look through your code, no element of change is modified anywhere under any condition (aside from the initial assignment when you set all elements to 1.) I don't think it's really suited well to help with your backtracking, anyway. You might consider a stack of the board positions you've changed.
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