SRM469 Div1 Easy

250

class TheMoviesLevelOneDivOne {
public:
  long long find(int n, int m, vector <int> row, vector <int> seat) {
    
    lli ret = 0;
    ret += (lli)n * (lli)(m - 1);

    set< pair< pair<int, int>, pair<int, int> > > taboo;
    for (int i = 0; i < row.size(); ++i) {
      int x = row[i], y = seat[i];
        pair<int, int> a = make_pair(x, y);
        pair<int, int> b = make_pair(x, y - 1);
        pair<int, int> c = make_pair(x, y + 1);
        if (y != 1) {
          taboo.insert( make_pair(b, a) );
        }
        if (y != m) {
          taboo.insert( make_pair(a, c) );
        }
    }

    return ret - (lli)taboo.size();
  }

};