public void Action(position[,] state, ref List<stepmove> r)
{
// List<stepmove> r = new List<stepmove>();
for (int i = 0; i < 7; i++)
{
for (int j = 5; j >= 0; j--)
{
if (!state[i, j].occupied)
{
stepmove temp = new stepmove();
temp.pos = state[i, j].pos;
temp.score = double.MinValue;
r.Add(temp);
break;
}
}
}
// return r;
}
public bool winstate(position[,] state, int pcolor)
{
//Horizontal
for (int i = 0; i < 7; i++)
{
for (int j = 0; j < 6 - 3; j++)
{
if (state[i,j].occupied&&(state[i, j].color == pcolor) && state[i,j+1].occupied&&(state[i, j+1].color == pcolor) && state[i,j+2].occupied&&(state[i, j+2].color == pcolor) && state[i,j+3].occupied&&(state[i, j+3].color == pcolor))
{ start.X = i; start.Y = j; end.X = i; end.Y = j + 3; return true; }
}
}
//Vertical
for (int i = 0; i < 7 - 3; i++)
{
for (int j = 0; j < 6; j++)
{
if (state[i,j].occupied&&(state[i, j].color == pcolor) && state[i+1,j].occupied&&(state[i+1, j].color == pcolor) && state[i+2,j].occupied&&(state[i+2, j].color == pcolor) && state[i+3,j].occupied&&(state[i+3, j].color == pcolor))
{ start.X = i; start.Y = j; end.X = i+3; end.Y = j; return true; }
}
}
//Diagonal
for (int i = 0; i < 7 - 3; i++)
{
for (int j = 0; j < 6 - 3; j++)
{
if (state[i, j].occupied && (state[i, j].color == pcolor) && state[i+1, j + 1].occupied && (state[i+1, j + 1].color == pcolor) && state[i+2, j + 2].occupied && (state[i+2, j + 2].color == pcolor) && state[i+3, j + 3].occupied && (state[i+3, j + 3].color == pcolor))
{ start.X = i; start.Y = j; end.X = i+3; end.Y = j + 3; return true; }
}
}
//Diagonal
for (int i = 0; i < 7 - 3; i++)
{
for (int j = 3; j < 6; j++)
{
if (state[i, j].occupied && (state[i, j].color == pcolor) && state[i + 1, j - 1].occupied && (state[i + 1, j - 1].color == pcolor) && state[i + 2, j - 2].occupied && (state[i + 2, j - 2].color == pcolor) && state[i + 3, j - 3].occupied && (state[i + 3, j - 3].color == pcolor))
{ start.X = i; start.Y = j; end.X = i+3; end.Y = j - 3; return true; }
}
}
return false;
}
public void result(position[,] state, stepmove a,int pcolor)
{
state[a.pos.X, a.pos.Y].pos = a.pos;
state[a.pos.X, a.pos.Y].occupied = true;
state[a.pos.X, a.pos.Y].color = pcolor;
//return state;
}
public double score(position[,] state,int pcolor)
{
double score = 0;
double scoreTwo = 10;
double scoreThree = 40;
for (int i = 0; i < 7; i++)
{
for (int j = 0; j < 6; j++)
{
if (state[i, j].occupied == true)
{
//Vertical 2
if (j < 6 - 2)
{
if ((state[i, j + 1].color == pcolor) && (state[i, j + 2].color == pcolor))
score += scoreTwo;
}
//Vertical 2~
if (j >= 2)
{
if ((state[i, j - 1].color == pcolor) && (state[i, j - 2].color == pcolor))
score += scoreTwo;
}
//Horizontal 2
if (i < 7 - 2)
{
if ((state[i + 1, j].color == pcolor) && (state[i + 2, j].color == pcolor))
score += scoreTwo;
//Diagonal 2
if (j < 6 - 2)
{
if ((state[i + 1, j + 1].color == pcolor) && (state[i + 2, j + 2].color == pcolor))
score += scoreTwo;
}
if (j >= 2)
{
if ((state[i + 1, j - 1].color == pcolor) && (state[i + 2, j - 2].color == pcolor))
score += scoreTwo;
}
}
//Horizontal 2~
if (i >= 2)
{
if ((state[i - 1, j].color == pcolor) && (state[i - 2, j].color == pcolor))
score += scoreTwo;
//Diagonal 2~
if (j < 6 - 2)
{
if ((state[i - 1, j + 1].color == pcolor) && (state[i - 2, j + 2].color == pcolor))
score += scoreTwo;
}
if (j >= 2)
{
if ((state[i - 1, j - 1].color == pcolor) && (state[i - 2, j - 2].color == pcolor))
score += scoreTwo;
}
}
//Vertical 3
if (j < 6 - 3)
{
if ((state[i, j + 1].color == pcolor) && (state[i, j + 2].color == pcolor) && (state[i, j + 3].color == pcolor))
score += scoreThree;
}
//Vertical 3~
if (j >= 3)
{
if ((state[i, j - 1].color == pcolor) && (state[i, j - 2].color == pcolor) && (state[i, j - 3].color == pcolor))
score += scoreThree;
}
//Horizontal 3
if (i < 7 - 3)
{
if ((state[i + 1, j].color == pcolor) && (state[i + 2, j].color == pcolor) && (state[i + 3, j].color == pcolor))
score += scoreThree;
//Diagonal 3
if (j < 6 - 3)
{
if ((state[i + 1, j + 1].color == pcolor) && (state[i + 2, j + 2].color == pcolor) && (state[i + 3, j + 3].color == pcolor))
score += scoreThree;
}
if (j >= 3)
{
if ((state[i + 1, j - 1].color == pcolor) && (state[i + 2, j - 2].color == pcolor) && (state[i + 3, j - 3].color == pcolor))
score += scoreThree;
}
}
//Horizontal 3~
if (i >= 3)
{
if ((state[i - 1, j].color == pcolor) && (state[i - 2, j].color == pcolor) && (state[i - 3, j].color == pcolor))
score += scoreThree;
//Diagonal 3~
if (j < 6 - 3)
{
if ((state[i - 1, j + 1].color == pcolor) && (state[i - 2, j + 2].color == pcolor) && (state[i - 3, j + 3].color == pcolor))
score += scoreThree;
}
if (j >= 3)
{
if ((state[i - 1, j - 1].color == pcolor) && (state[i - 2, j - 2].color == pcolor) && (state[i - 3, j - 3].color == pcolor))
score += scoreThree;
}
}
}
}
}
return score;
}
public stepmove MinValue(position[,] s, stepmove next,double alpha, double beta, int depth)
{
position[,] state2 = new position[7, 6];
for (int i = 0; i < 7; i++)
{
for (int j = 0; j < 6; j++)
{
state2[i, j].pos.X = s[i, j].pos.X;
state2[i, j].pos.Y = s[i, j].pos.Y;
state2[i, j].color = s[i, j].color;
state2[i, j].occupied = s[i, j].occupied;
}
}
result(state2, next, 1);
stepmove v;
v.score = double.MaxValue;
v.pos = next.pos;
if (cutoff(state2, depth, 1))
{
v.score = evaluation(state2, 1);
return v;
}
List<stepmove> actionlist = new List<stepmove>();
Action(state2, ref actionlist);
foreach (stepmove a in actionlist)
{
v.score = Math.Min(v.score, MaxValue(state2, a, alpha, beta, depth + 1).score);
if (v.score <= alpha)
return v;
beta = Math.Min(beta, v.score);
}
return v;
}
/*
public bool isWin(int col, int row, position[,] state)
{
int connect = 1;
//check right:
for (int i = 1; i <= 3; i++)
{
if(col+i>6)
break;
else
{
if (state[col + i, row].occupied == false)
break;
else
{
if (state[col + i, row].color == player)
connect++;
else
break;
}
}
}
if (connect == 4)
return true;
//check left:
for (int i = 1; i <= 3; i++)
{
if (col - i < 0)
break;
else
{
if (state[col - i, row].occupied == true)
{
if (state[col - i, row].color == player)
connect++;
else
break;
}
else
break;
}
}
if (connect == 4)
return true;
connect = 1;
//check up:
for (int i = 1; i <= 3; i++)
{
if (row - i < 0)
break;
else
{
if (state[col, row - i].occupied == true)
{
if (state[col, row - i].color == player)
connect++;
else
break;
}
else
break;
}
}
if (connect == 4)
return true;
//check down:
for (int i = 1; i <= 3; i++)
{
if (row + i > 5)
break;
else
{
if (state[col, row + i].occupied == true)
{
if (state[col, row + i].color == player)
connect++;
else
break;
}
else
break;
}
}
if (connect == 4)
return true;
connect = 1;
//check upright:
for (int i = 1; i <= 3; i++)
{
if (col + i > 6 || row - i < 0)
break;
else
{
if (state[col + i, row - i].occupied == true)
{
if (state[col + i, row - i].color == player)
connect++;
else
break;
}
else
break;
}
}
if (connect == 4)
return true;
//check leftbottom:
for (int i = 1; i <= 3; i++)
{
if (col - i < 0 || row + i > 5)
break;
else
{
if (state[col - i, row + i].occupied == true)
{
if (state[col - i, row + i].color == player)
connect++;
else
break;
}
else
break;
}
}
if (connect == 4)
return true;
connect = 1;
//check upleft:
for (int i = 1; i <= 3; i++)
{
if (col - i < 0 || row - i < 0)
break;
else
{
if (state[col - i, row - i].occupied == true)
{
if (state[col - i, row - i].color == player)
connect++;
else
break;
}
else
break;
}
}
if (connect == 4)
return true;
//check bottomright:
for (int i = 1; i <= 3; i++)
{
if (col + i > 6 || row + i > 5)
break;
else
{
if (state[col + i, row + i].occupied == true)
{
if (state[col + i, row + i].color == player)
connect++;
else
break;
}
else
break;
}
}
if (connect == 4)
return true;
return false;
}*/
public bool isDraw(position[,] state)
{
int sum = 0;
for (int i = 0; i < 7; i++)
{
if (state[i, 0].occupied == true)
sum++;
}
if (sum == 7)
return true;
else
return false;
}
public int hminimax(int depth)
{
position[,] state = new position[7, 6];
for (int i = 0; i < 7; i++)
{
for (int j = 0; j < 6; j++)
{
state[i,j].pos.X=board[i, j].pos.X;
state[i, j].pos.Y=board[i, j].pos.Y;
state[i, j].color = board[i, j].color;
state[i, j].occupied=board[i, j].occupied;
}
}
//state[,] is a thinking board for minimax algorithm
//v contains each action return move(position and score), r is for the final return value
//1 is for human
// double v = MaxValue(state, double.MinValue, double.MaxValue,depth);
stepmove v,r;
r.score = double.MaxValue;
r.pos.X = -1;
r.pos.Y = -1;
List<stepmove> actionlist=new List<stepmove>();
Action(state, ref actionlist);
foreach (stepmove a in actionlist)
{
v = MaxValue(state, a,double.MinValue, double.MaxValue, 1);
if (v.score <= r.score)
r = v;
}
return r.pos.X;
}
public double evaluation(position[,] state, int pcolor)
{
if (winstate(state, pcolor))
{
if (pcolor == 2)//computer
return double.MinValue;
else
return double.MaxValue;
}
return score(state, 2) - score(state, 1);
}
public bool cutoff(position[,] state, int depth,int pcolor)
{
if(winstate(state,pcolor))
return true;
else if(depth>Maxlevel)
return true;
else
return false;
}