1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
#include <bits/stdc++.h>
#define MX 500005
using namespace std;
int n, X, Y, x[MX][2], y[MX][2], N = -1, res;
int dp[5005][5005];
map<int, int> M, id, cnt, los;
void dodaj(int left, int up, int right, int down, int val) {
    if(!los[abs(val)]) los[abs(val)] = rand() % 1158294941;
    if(val < 0)
        val = -los[abs(val)];
    else val = los[abs(val)];
    //cout << left << " " << up << " " << right << " " << down << " " << val<<  endl;
    dp[left][up] += val;
    dp[right + 1][up] -= val;
    dp[left][down + 1] -= val;
    dp[right + 1][down + 1] += val;
}
int main() {
    cin >> n >> X >> Y;
    M[0] = M[X] = M[Y] = 1;
    for(int i = 1; i <= n; i++) {
        cin >> x[i][0] >> y[i][0] >> x[i][1] >> y[i][1];
        for(int k = 0; k < 2; k++) {
            for(int j = -1; j <= 1; j++)
                if(x[i][k] + j <= X && x[i][k] + j >= 0) M[x[i][k] + j] = 1;
            for(int j = -1; j <= 1; j++)
                if(y[i][k] + j <= Y && y[i][k] + j >= 0) M[y[i][k] + j] = 1;
        }
    }
    for(auto &i : M) {
        i.second = ++N;
        id[N] = i.first;
    }
    X = M[X]; Y = M[Y];
    for(int i = 1; i <= n; i++) {
        //cout << i << endl;
        for(int j = 0; j < 2; j++)
            x[i][j] = M[x[i][j]], y[i][j] = M[y[i][j]];
        if(x[i][0] > x[i][1]) swap(x[i][0], x[i][1]);
        if(y[i][0] > y[i][1]) swap(y[i][0], y[i][1]);
        //zwykly prostokat
        dodaj(x[i][0] + 1, y[i][0] + 1, x[i][1], y[i][1], 4 * i + 0);
        //pasek poziomy - prostokat
        dodaj(1, y[i][0] + 1, X, y[i][1], 4 * i  + 1);
        dodaj(x[i][0] + 1, y[i][0] + 1, x[i][1], y[i][1], -(4 * i + 1));
        // pasek pionowy - prostokat
        dodaj(x[i][0] + 1, 1, x[i][1], Y, 4 * i + 2);
        dodaj(x[i][0] + 1, y[i][0] + 1, x[i][1], y[i][1], -(4 * i + 2));
        //  cale - pion - poziom + prostokat
        dodaj(1, 1, X, Y, 4 * i + 3);
        dodaj(1, y[i][0] + 1, X, y[i][1], -(4 * i + 3));
        dodaj(x[i][0] + 1, 1, x[i][1], Y, -(4 * i + 3));
        dodaj(x[i][0] + 1, y[i][0] + 1, x[i][1], y[i][1], 4 * i + 3);
    }
    for(int i = 1; i <= X; i++) {
        for(int j = 1; j <= Y; j++) {
            dp[i][j] += dp[i][j - 1] + dp[i - 1][j] - dp[i - 1][j - 1];
            cnt[dp[i][j]] += (id[i] - id[i - 1]) * (id[j] - id[j - 1]);
            res = max(res, cnt[dp[i][j]]);
            //cout << (id[i] - id[i - 1]) * (id[j] - id[j - 1]) << "\n";
            //cout << dp[i][j] << "\t";
        }//cout << "\n";
    }
    for(int j = Y; j >= 1; j--) {
        for(int i = 1; i <= X; i++) {
            //cout << dp[i][j] << "\t";
        }//cout << "\n";
    }
    cout << res << "\n";
}