Submission #617301

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Source Code Expand

#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <cfloat>
#include <ctime>
#include <cassert>
#include <map>
#include <utility>
#include <set>
#include <iostream>
#include <memory>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <sstream>
#include <complex>
#include <stack>
#include <queue>
#include <numeric>
#include <list>
#include <iomanip>
#include <fstream>
#include <bitset>

using namespace std;

#define foreach(it, c) for (__typeof__((c).begin()) it=(c).begin(); it != (c).end(); ++it)
template <typename T> void print_container(ostream& os, const T& c) { const char* _s = " "; if (!c.empty()) { __typeof__(c.begin()) last = --c.end(); foreach (it, c) { os << *it; if (it != last) os << _s; } } }
template <typename T> ostream& operator<<(ostream& os, const vector<T>& c) { print_container(os, c); return os; }
template <typename T> ostream& operator<<(ostream& os, const set<T>& c) { print_container(os, c); return os; }
template <typename T> ostream& operator<<(ostream& os, const multiset<T>& c) { print_container(os, c); return os; }
template <typename T> ostream& operator<<(ostream& os, const deque<T>& c) { print_container(os, c); return os; }
template <typename T, typename U> ostream& operator<<(ostream& os, const map<T, U>& c) { print_container(os, c); return os; }
template <typename T, typename U> ostream& operator<<(ostream& os, const pair<T, U>& p) { os << "(" << p.first << ", " << p.second << ")"; return os; }

template <typename T> void print(T a, int n, const string& split = " ") { for (int i = 0; i < n; i++) { cout << a[i]; if (i + 1 != n) cout << split; } cout << endl; }
template <typename T> void print2d(T a, int w, int h, int width = -1, int br = 0) { for (int i = 0; i < h; ++i) { for (int j = 0; j < w; ++j) { if (width != -1) cout.width(width); cout << a[i][j] << ' '; } cout << endl; } while (br--) cout << endl; }
template <typename T> void input(T& a, int n) { for (int i = 0; i < n; ++i) cin >> a[i]; }
#define dump(v) (cout << #v << ": " << v << endl)

#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
#define erep(i, n) for (int i = 0; i <= (int)(n); ++i)
#define all(a) (a).begin(), (a).end()
#define rall(a) (a).rbegin(), (a).rend()
#define clr(a, x) memset(a, x, sizeof(a))
#define sz(a) ((int)(a).size())
#define mp(a, b) make_pair(a, b)
#define ten(n) ((long long)(1e##n))

template <typename T, typename U> void upmin(T& a, const U& b) { a = min<T>(a, b); }
template <typename T, typename U> void upmax(T& a, const U& b) { a = max<T>(a, b); }
template <typename T> void uniq(T& a) { sort(a.begin(), a.end()); a.erase(unique(a.begin(), a.end()), a.end()); }
template <class T> string to_s(const T& a) { ostringstream os; os << a; return os.str(); }
template <class T> T to_T(const string& s) { istringstream is(s); T res; is >> res; return res; }
void fast_io() { cin.tie(0); ios::sync_with_stdio(false); }
bool in_rect(int x, int y, int w, int h) { return 0 <= x && x < w && 0 <= y && y < h; }

typedef long long ll;
typedef pair<int, int> pint;

const int dx[] = { 0, 1, 0, -1 };
const int dy[] = { 1, 0, -1, 0 };


template <typename T>
class Sum2d 
{
public:
    int width, height;
    vector<vector<T>> cum;
    Sum2d(const vector<vector<T>>& a)
        : width(a[0].size()), height(a.size()), cum(height + 1, vector<T>(width + 1))
    {
        for (int y = 0; y < height; ++y)
            for (int x = 0; x < width; ++x)
                cum[y + 1][x + 1] = cum[y][x + 1] + cum[y + 1][x] - cum[y][x] + a[y][x];
    }
    Sum2d() {}

    T get_sum(int x1, int x2, int y1, int y2) const
    {
        assert(0 <= x1 && x1 <= x2 && x2 <= width);
        assert(0 <= y1 && y1 <= y2 && y2 <= height);
        return cum[y2][x2] - cum[y1][x2] - cum[y2][x1] + cum[y1][x1];
    }

    T get_sum_by_len(int x, int y, int w, int h) const
    {
        assert(0 <= x && x + w <= width);
        assert(0 <= y && y + h <= height);
        return cum[y + h][x + w] - cum[y][x + w] - cum[y + h][x] + cum[y][x];
    }
};
int main()
{
    fast_io();

    int h, w;
    cin >> h >> w;
    vector<vector<ll>> b(h, vector<ll>(w));
    rep(y, h) rep(x, w)
        cin >> b[y][x];

    Sum2d<ll> sum(b);
    ll max_left[333], max_right[333], max_down[333], max_up[333];

    {
        max_left[0] = -ten(18);
        for (int high_x = 1; high_x <= w; ++high_x)
        {
            max_left[high_x] = max_left[high_x - 1];
            rep(low_x, high_x)
            {
                ll max_b = -ten(18);
                ll min_b = ten(18);
                rep(high_y, h + 1)
                {
                    ll cur = sum.get_sum(low_x, high_x, 0, high_y);
                    upmax(max_b, cur - min_b);
                    upmin(min_b, cur);
                }
                upmax(max_left[high_x], max_b);
            }
        }
    }
    {
        max_right[w] = -ten(18);
        for (int low_x = w - 1; low_x >= 0; --low_x)
        {
            max_right[low_x] = max_right[low_x + 1];
            for (int high_x = low_x + 1; high_x <= w; ++high_x)
            {
                ll max_b = -ten(18);
                ll min_b = ten(18);
                rep(high_y, h + 1)
                {
                    ll cur = sum.get_sum(low_x, high_x, 0, high_y);
                    upmax(max_b, cur - min_b);
                    upmin(min_b, cur);
                }
                upmax(max_right[low_x], max_b);
            }
        }
    }
    {
        max_down[0] = -ten(18);
        for (int high_y = 1; high_y <= h; ++high_y)
        {
            max_down[high_y] = max_down[high_y - 1];
            rep(low_y, high_y)
            {
                ll max_b = -ten(18);
                ll min_b = ten(18);
                rep(high_x, w + 1)
                {
                    ll cur = sum.get_sum(0, high_x, low_y, high_y);
                    upmax(max_b, cur - min_b);
                    upmin(min_b, cur);
                }
                upmax(max_down[high_y], max_b);
            }
        }
    }
    {
        max_up[h] = -ten(18);
        for (int low_y = h - 1; low_y >= 0; --low_y)
        {
            max_up[low_y] = max_up[low_y + 1];
            for (int high_y = low_y + 1; high_y <= h; ++high_y)
            {
                ll max_b = -ten(18);
                ll min_b = ten(18);
                rep(high_x, w + 1)
                {
                    ll cur = sum.get_sum(0, high_x, low_y, high_y);
                    upmax(max_b, cur - min_b);
                    upmin(min_b, cur);
                }
                upmax(max_up[low_y], max_b);
            }
        }
    }
//     print(max_left, w + 1);
//     print(max_right, w + 1);
//     print(max_down, h + 1);
//     print(max_up, h + 1);

    ll res = -ten(18);
    {
        for (int high_x = 1; high_x <= w; ++high_x)
        {
            rep(low_x, high_x)
            {
                ll min_b = ten(18);
                rep(high_y, h + 1)
                {
                    ll cur = sum.get_sum(low_x, high_x, 0, high_y);
                    upmax(res, cur - min_b + max(max(max_left[low_x], max_right[high_x]), max_up[high_y]));
                    upmin(min_b, cur);
                }
            }
        }
    }
    cout << res << endl;
}

Submission Info

Judge Result