The int winner
should be set to 2 under certain conditions but it's somehow being set to a variety of higher values, most commonly 6. I have no idea how this is happening, as there is no other function in my class that affects winner
, and the variable isn't even mentioned anywhere else in the program. What is most confusing to me is that I have an almost identical function (P2Move()
) that is literally identical in how it sets the winner
variable to P1Move()
, and that function runs perfectly.
Some info: The class this is part of is called Board, which acts as a checkerboard array made up of Square class objects.
Below is the function causing the problem. Near the bottom, the statement else if((canTake.size()==0)&&(canMove.size()==0)) {Board::winner = 2;}
causes the problem. Everything else seems to work when I remove the problematic part from the function, but I need that part to work in order to submit the final project.
void Board::P1Move()
{
P1pieces = 0;
std::vector <Move> canMove;
std::vector <Move> canTake;
for(int j = 0; j < bSize; j++)
{ //Start of j loop.
for(int i = 0; i < bSize; i++)
{ //Start of i loop.
Square sq = board[i][j];
bool cTakeL = canTakeL(i,j);
bool cTakeR = canTakeR(i,j);
bool cMoveL = canMoveL(i,j);
bool cMoveR = canMoveR(i,j);
if(board[i][j].getPl() == P1)
{
P1pieces++;
if(cTakeL)
{
Move a = Move(sq.getIndex(),board[i-2][j+2].getIndex(),board[i-1][j+1].getIndex(),0);
canTake.push_back(a);
}
if(cTakeR)
{
Move b = Move(sq.getIndex(),board[i+2][j+2].getIndex(),board[i+1][j+1].getIndex(),0);
canTake.push_back(b);
}
if(cMoveL)
{
Move c = Move(sq.getIndex(),board[i-1][j+1].getIndex(),0,0);
canMove.push_back(c);
}
if(cMoveR)
{
Move d = Move(sq.getIndex(),board[i+1][j+1].getIndex(),0,0);
setWinner(d.getSpos());
canMove.push_back(d);
}
}
} //End of i loop.
} //End of j loop.
if(canTake.size()!=0)
{
time_t t;
time(&t);
srand(t);
int moveNum = rand()%canTake.size();
std::string output = "p1 ";
Move out = canTake.at(moveNum);
int i = 0;
int j = 0;
for(int y = 0; y < bSize; y++)
{
for(int x = 0; x < bSize; x++)
{
if(board[x][y].getIndex()==out.getSpos())
{
i = x;
j = y;
}
}
}
if(board[i-2][j+2].getIndex()==out.getEndPos())
{
board[i-2][j+2].setOcc(true);
board[i-2][j+2].setPl(P1);
board[i-1][j+1].setOcc(false);
board[i-1][j+1].setPl(NA);
}
else if(board[i+2][j+2].getIndex()==out.getEndPos())
{
board[i+2][j+2].setOcc(true);
board[i+2][j+2].setPl(P1);
board[i+1][j+1].setOcc(false);
board[i+1][j+1].setPl(NA);
}
output = output + out.toString();
setCmove(output);
board[i][j].setOcc(false);
board[i][j].setPl(NA);
}
else if(canMove.size()!=0)
{
time_t t;
time(&t);
srand(t);
int moveNum = rand()%canMove.size();
std::string output = "p1 ";
Move out = canMove.at(moveNum);
int i = 0;
int j = 0;
for(int y = 0; y < bSize; y++)
{
for(int x = 0; x < bSize; x++)
{
if(board[x][y].getIndex()==out.getSpos())
{
i = x;
j = y;
}
}
}
if(board[i-1][j+1].getIndex()==out.getEndPos())
{
board[i-1][j+1].setOcc(true);
board[i-1][j+1].setPl(P1);
}
else if(board[i+1][j+1].getIndex()==out.getEndPos())
{
board[i+1][j+1].setOcc(true);
board[i+1][j+1].setPl(P1);
}
output = output + out.toString();
setCmove(output);
board[i][j].setOcc(false);
board[i][j].setPl(NA);
}
else if((canTake.size()==0)&&(canMove.size()==0))
{
Board::winner = 2;
}
P1pieces = canTake.size() + canMove.size();
}
You are working with std::vector
, which is a good thing. (Too much beginner "C++" code uses C arrays.) The vector
class template allows for a pretty easy way to find out if and where you might have an out-of-bounds access (as suggested in the comments):
Instead of accessing vector elements using operator[]
, change your code to use the .at()
member function. .at()
is bounds-checking, and will throw an exception if you access out-of-bounds (instead of silently breaking your program).
In production code, operator[]
is usually preferred as omitting the bounds check is more efficient. But while learning, .at()
can help you quite a bit.
Also, getting in the habit of using code checkers like valgrind or the assert
macro to check your assumptions is a good thing, even when you got past the point where you wouldn't use .at()
anymore.