int solve(){
memset(tick, 0x1f, sizeof(tick));
Pos start = findCh('S');
Pos target = findCh('T');
//start.display("S");
//start.display("T");
queue<Pos> Q;
Q.push(start);
tick[start.x][start.y][start.color][start.dir] = 0;
while (Q.size()){
Pos s = Q.front(); Q.pop();
//s.display("Pop");
for (int i = 0; i < 3; i++){
Pos t = s.action(i);
if (!t.isValid()) continue;
if (tick[t.x][t.y][t.color][t.dir] != INF) continue;
if (grid[t.x][t.y] == '#') continue;
tick[t.x][t.y][t.color][t.dir] = tick[s.x][s.y][s.color][s.dir] + 1;
Q.push(t);
//s.display(" Push");
}
}
int best = INF;
for (int i = 0; i < 4; i++){
target.dir = i;
best = min(best, tick[target.x][target.y][target.color][target.dir]);
}
return best;
}
