Submission #1942307

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Source Code Expand

import std.algorithm;
import std.array;
import std.ascii;
import std.bigint;
import std.complex;
import std.container;
import std.conv;
import std.functional;
import std.math;
import std.range;
import std.stdio;
import std.string;
import std.typecons;

auto readInts() {
	return array(map!(to!int)(readln().strip().split()));
}
auto readInt() {
	return readInts()[0];
}
auto readLongs() {
	return array(map!(to!long)(readln().strip().split()));
}
auto readLong() {
	return readLongs()[0];
}

void readlnTo(T...)(ref T t) {
    auto s = readln().split();
    assert(s.length == t.length);
    foreach(ref ti; t) {
        ti = s[0].to!(typeof(ti));
        s = s[1..$];
    }
}

class UnionFindTree {
public:
    this(size_t n) {
        parent = iota(n).array();
        rank = new size_t[](n);
    }
    size_t find(size_t n) {
        if(n == parent[n]) {
            return n;
        } else {
            parent[n] = find(parent[n]);
            return parent[n];
        }
    }
    void unite(size_t n, size_t m) {
        auto p1 = find(n);
        auto p2 = find(m);
        if(n == m) {
            return;
        }
        if(rank[p1] < rank[p2]) {
            swap(p1, p2);
        }
        if(rank[p1] == rank[p2]) {
            ++rank[p1];
        }
        parent[p2] = p1;
    }
private:
    size_t[] parent;
    size_t[] rank;
}
unittest {
    auto uft = new UnionFindTree(10);
    foreach(i; iota(10)) {
        assert(uft.find(i) == i);
    }
    foreach(i; iota(10).filter!(a => a%3 == 0).drop(1)) {
        uft.unite(i, i-3);
    }
    foreach(i; iota(10).filter!(a => a%3 == 0)) {
        assert(uft.find(0) == uft.find(i));
    }
    foreach(i; iota(10).filter!(a => a%3 != 0)) {
        assert(uft.find(0) != uft.find(i));
    }
}

const real eps = 1e-10;

const long p = 1_000_000_000 + 7;

long sign(long n) {
    return n % 2 == 1 ? -1: 1;
}

void main(){
    long h, w;
    readlnTo(h, w);

    long[][] c;
    foreach(i; iota(h)) {
        c ~= readLongs();
    }

    auto s = new long[][](h+1, w+1);
    foreach(i; iota(h)) {
        foreach(j; iota(w)) { 
            s[i+1][j+1] = s[i+1][j] + c[i][j] * sign(i + j);
        }
    }
    foreach(i; iota(h)) {
        foreach(j; iota(w+1)) {
            s[i+1][j] += s[i][j];
        }
    }

    long ans;
    foreach(i; iota(h)) {
        foreach(j; iota(w)) {
            foreach(k; iota(i+1, h+1)) {
                foreach(l; iota(j+1, w+1)) {
                    if(s[k][l] - s[k][j] - s[i][l] + s[i][j] == 0) {
                        ans = max(ans, (k-i) * (l - j));
                    }
                }
            }
        }
    }
    writeln(ans);
}

Submission Info

Judge Result