Topcoder Inv 2001 Semi A+B 500 pointer (brief version)

Tothello_small.cpp

#include <bits/stdc++.h>
#define mp make_pair
#define vstr vector<string>
#define pb push_back
#define all(x) begin(x), end(x)
#define sz(x) int(x.size())
#define P(X) cout << X << "\t"
#define NL cout << endl
#define FOR(I,N) for(int I = 0; I < N; ++I)

using namespace std;

typedef pair<int, int> Coord;
typedef pair<int, int> Incr;
static constexpr Incr UP = mp(-1, 0), DN = mp(1, 0), LT = mp(0, -1), RT = mp(0, 1);
static constexpr Incr NE = mp(-1, 1), NW = mp(-1, -1), SE = mp(1, 1), SW = mp(1, -1);

struct Tothello
{
    typedef vector<vector<int>> Board;
    Board board;
    
    int doCount(const Board &b)
    {
        int cnt = 0;
        FOR(i, 8) cnt += count(all(b[i]), 1);
        return cnt;
    }
    
    int applyone(Board &b, const Coord &c, const Incr &i1, const Incr &i2)
    {
        int cnt = 0;
        for(Iter2d<int> it(b, c, i1), ite = it.end(); it != ite; ++it)
        {
            auto it1 = it(i2), ite2 = it1.end();
            auto it2 = adjacent_find(it1, ite2, [](int a, int b) {return a==1 && b==0;});
            auto it3 = adjacent_find(it2, ite2, [](int a, int b) {return a==0 && b==1;});
            if(it2 && it3 && distance(it2,it3) == count(it2, it3.next(), 0))
            {
                fill(it2, it3.next(), 1);
                ++cnt;
            }
        }
        return cnt;
    }
    
    void apply(Board &b)
    {
        int cnt;
        do
        {
            cnt = 0;
            cnt += applyone(b, mp(0, 0), DN, RT);
            cnt += applyone(b, mp(0, 0), RT, DN);
            cnt += applyone(b, mp(0, 7), LT, SW);
            cnt += applyone(b, mp(1, 7), DN, SW);
            cnt += applyone(b, mp(0, 0), RT, SE);
            cnt += applyone(b, mp(1, 0), DN, SE);
        }
        while(cnt);
    }
    
    int bestMove(vector<string> red, vector<string> blk, string who)
    {
        FOR(i, 8) board.pb(vector<int>(8, -1));
        
        int w = (who == "Red" ? 1 : 0);
        for(const auto &s:red) board[s[0]-'A'][s[1]-'1'] = w;
        for(const auto &s:blk) board[s[0]-'A'][s[1]-'1'] = w^1;
        
        int maxcnt = doCount(board);
        FOR(i, 8) FOR(j, 8)
        {
            if(board[i][j] < 0)
            {
                Board temp = board;
                temp[i][j] = 1;
                apply(temp);
                maxcnt = max(maxcnt, doCount(temp));
            }
        }
        
        return maxcnt;
    }
};