Action CatAgent::getAction(const GameState& state) const {
const vector<Action> actions = state.getActions(idx_);
const Position& mousePosition = state.getMousePosition();
Action minDistAction;
double minManDist = kInfinity;
double minDist = kInfinity;
vector<Action> bestActions;
for (size_t i = 0; i < actions.size(); i++) {
double dist = Utils::manhattanDistance(actions[i].to, mousePosition);
if (dist < minManDist) {
minManDist = dist;
minDist = Utils::minDistance(actions[i].to, mousePosition);
bestActions.clear();
bestActions.push_back(actions[i]);
} else if (dist == minManDist) {
dist = Utils::minDistance(actions[i].to, mousePosition);
if (dist < minDist) {
minDist = dist;
bestActions.clear();
bestActions.push_back(actions[i]);
} else if (dist == minDist) {
// Wow, truly a tie
bestActions.push_back(actions[i]);
}
}
}
return bestActions.at(state.getTime() % bestActions.size());
}
double MouseAgent::alphaBeta(
const GameState& state,
int level,
double alpha,
double beta,
Action* actionPtr) const {
if (state.gameOver() ||
level == (kAlphaBetaDepth * state.getNumAgents())) {
return evaluate(state);
}
int agentIndex = level % state.getNumAgents();
bool isMax = (agentIndex == 0);
double value = isMax ? -kInfinity : kInfinity;
vector<Action> actions = isMax
? state.getActions(agentIndex)
: vector<Action>(1, cats_[agentIndex - 1].getAction(state));
vector<Action> bestActions;
for (size_t i = 0; i < actions.size(); i++) {
const GameState successor = state.getNext(actions[i]);
double nextV = alphaBeta(successor, level + 1, alpha, beta, actionPtr);
if (isMax) {
if (value < nextV) {
if (level == 0) {
bestActions.clear();
bestActions.push_back(actions[i]);
}
value = nextV;
} else if ((value == nextV) && (level == 0)) {
bestActions.push_back(actions[i]);
}
if (value >= beta) {
break;
}
alpha = max(alpha, value);
} else {
if (value > nextV) {
if (level == 0) {
bestActions.clear();
bestActions.push_back(actions[i]);
}
value = nextV;
} else if ((value == nextV) && (level == 0)) {
bestActions.push_back(actions[i]);
}
if (value <= alpha) {
break;
}
beta = min(beta, value);
}
}
if (level == 0) {
*actionPtr = bestActions.at(rand() % bestActions.size());
}
return value;
}
Action MouseAgent::getAction(const GameState& state) const {
//cout << "Value: " << MouseAgent::evaluate(state) << endl;
//exit(0);
vector<Action> actions = state.getActions(idx_);
Action bestAction;
double value = MouseAgent::alphaBeta(state, 0, -kInfinity, kInfinity, &bestAction);
//cout << "Value: " << evaluate(state);
//cout << "Action: " << bestAction.to.x << ", " << bestAction.to.y << endl;
//exit(0);
return bestAction;
}
Action KeyboardAgent::getAction(const GameState& state) const {
string input;
bool valid = false;
while (true) {
cin >> input;
char dir = input[0];
int dx = 0;
int dy = 0;
if (dir == 'w') {
dy = -1;
} else if (dir == 's') {
dy = 1;
} else if (dir == 'a') {
dx = -1;
} else if (dir == 'd') {
dx = 1;
} else {
continue;
}
vector<Action> actions = state.getActions(idx_);
unsigned int i;
for (i = 0; i < actions.size(); i++) {
int adx = actions[i].to.x - actions[i].from.x;
int ady = actions[i].to.y - actions[i].from.y;
if ((adx == dx) && (ady == dy)) {
valid = true;
break;
}
}
if (valid) {
return actions[i];
}
}
}
