Submission #1261336

#	Time	Username	Problem	Language	Result	Execution time	Memory
1261336		biank	축구 경기장 (IOI23_soccer)	C++20	100 / 100	2070 ms	361620 KiB

soccer

#include "soccer.h"
#include <bits/stdc++.h>
 
#define forsn(i, s, n) for (int i = int(s); i < int(n); i++)
#define forn(i, n) forsn(i, 0, n)
#define dforsn(i, s, n) for (int i = int(n) - 1; i >= int(s); i--)
#define dforn(i, n) dforsn(i, 0, n)
 
#define sz(x) int(x.size())
#define all(x) begin(x), end(x)
 
#define pb push_back
#define eb emplace_back
 
#define fst first
#define snd second
 
using namespace std;
 
using vi = vector<int>;
using ii = pair<int, int>;
using ll = long long;

const int MAX_N = 2005;

int pref[MAX_N][MAX_N], n;
vector<ii> ran[MAX_N];

int query(int i1, int i2, int j1, int j2) {
    i2++, j2++;
    return pref[i2][j2] - pref[i1][j2] - pref[i2][j1] + pref[i1][j1];
}

ii getMaximal(int i, int l, int r) {
    int lo = i, hi = n;
    while (hi - lo > 1) {
        int mid = (lo + hi) / 2;
        if (query(i, mid, l, r) == 0) lo = mid;
        else hi = mid;
    }
    int i2 = lo;
    lo = -1, hi = i;
    while (hi - lo > 1) {
        int mid = (lo + hi) / 2;
        if (query(mid, i, l, r) == 0) hi = mid;
        else lo = mid;
    }
    int i1 = hi;
    return ii{i1, i2};
}

vector<ii> getRanges(int i, int l, int r) {
    int lo = -1, hi = sz(ran[i]);
    while (hi - lo > 1) {
        int mid = (lo + hi) / 2;
        if (ran[i][mid].snd >= l) hi = mid;
        else lo = mid;
    }
    int j = hi;
    vector<ii> ret;
    while (j < sz(ran[i]) && ran[i][j].fst <= r) {
        ret.eb(max(ran[i][j].fst, l), min(ran[i][j].snd, r));
        j++;
    }
    return ret;
}

map<int, int> memo[MAX_N][MAX_N];

int dp(int i, int i1, int i2, int j1, int j2) {
    if (memo[j1][j2].count(i)) return memo[j1][j2][i];
    int &ret = memo[j1][j2][i];
    if (i1 > 0) for (auto [b1, b2] : getRanges(i1 - 1, j1, j2)) {
        auto [a1, a2] = getMaximal(i1 - 1, b1, b2);
        ret = max(ret, dp(i1 - 1, a1, a2, b1, b2) + (b2 - b1 + 1) * ((a2 - a1 + 1) - (i2 - i1 + 1)));
    }
    if (i2 + 1 < n) for (auto [b1, b2] : getRanges(i2 + 1, j1, j2)) {
        auto [a1, a2] = getMaximal(i2 + 1, b1, b2);
        ret = max(ret, dp(i2 + 1, a1, a2, b1, b2) + (b2 - b1 + 1) * ((a2 - a1 + 1) - (i2 - i1 + 1)));
    }
    return ret;
}


int biggest_stadium(int N, vector<vi> F) {
    n = N;
    forn(i, n) forn(j, n) pref[i + 1][j + 1] = pref[i][j + 1] + pref[i + 1][j] - pref[i][j] + F[i][j];
    forn(i, n) {
        forn(j, n) {
            if (F[i][j]) continue;
            if (j == 0 || F[i][j - 1]) {
                ran[i].eb(j, j);
            } else {
                ran[i].back().snd++;
            }
        }
    }
    int ret = 0;
    forn(i, n) for (auto [j1, j2] : ran[i]) {
        auto [i1, i2] = getMaximal(i, j1, j2);
        ret = max(ret, dp(i, i1, i2, j1, j2) + (j2 - j1 + 1) * (i2 - i1 + 1));
    }
    return ret;
}

• Subtask 0: 0 / 0
• Subtask 1: 6 / 6
• Subtask 2: 8 / 8
• Subtask 3: 22 / 22
• Subtask 4: 18 / 18
• Subtask 5: 16 / 16
• Subtask 6: 30 / 30