Submission #1065373

#	Time	Username	Problem	Language	Result	Execution time	Memory
1065373		Gromp15	Soccer Stadium (IOI23_soccer)	C++17	65.50 / 100	308 ms	32028 KiB

soccer

#include <bits/stdc++.h>
#include "soccer.h"
#define ar array
#define ll long long
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
using namespace std;
template<typename T> bool ckmin(T &a, const T &b) { return a > b ? a = b, 1 : 0; }
template<typename T> bool ckmax(T &a, const T &b) { return a < b ? a = b, 1 : 0; }

const int nax = 31;
int dp[nax][nax][nax][nax];
int biggest_stadium(int n, std::vector<std::vector<int>> F)
{
	int sx = -1, sy = -1;
	bool one = 1;
	for (int i = 0; i < n; i++) for (int j = 0; j < n; j++) {
		if (F[i][j]) {
			if (~sx) one = 0;
			sx = i, sy = j;
		}
	}
	if (one) {
		return n*n - min(sx+1, n-sx) * min(sy+1, n-sy);
	}
	if (n > 30) {
		vector<ar<int, 2>> ints(n);
		int L = -1, R = -1;
		for (int i = 0; i < n; i++) {
			int u = 0;
			for (int j = 0; j < n; j++) if (!F[i][j]) {
				int r = j;
				while (r+1 < n && !F[i][r+1]) r++;
				ints[i] = {j, r};
				if (++u == 2) return 0;
				j = r;
			}
			if (u) {
				if (!~L) L = i;
				else {
					if (R != i-1) return 0;
				}
				R = i;
			}
		}
		int len = -1, idx = -1;
		for (int i = L; i <= R; i++) {
			if (ckmax(len, ints[i][1] - ints[i][0])) idx = i;
		}
		for (int i = idx-1; i >= L; i--) {
			if (!(ints[i][0] >= ints[i+1][0] && ints[i][1] <= ints[i+1][1])) {
				return 0;
			}
		}
		for (int i = idx+1; i <= R; i++) {
			if (!(ints[i][0] >= ints[i-1][0] && ints[i][1] <= ints[i-1][1])) {
				return 0;
			}
		}
		for (int i = L; i <= R; i++) {
			for (int j = L; j <= R; j++) {
				auto [L1, R1] = ints[i];
				auto [L2, R2] = ints[j];
				if (L1 > L2 || (L1 == L2 && R1 < R2)) swap(L1, L2), swap(R1, R2);
				if (R1 < R2) return 0;
			}
		}
		int tot = 0;
		for (int i = 0; i < n; i++) for (int j = 0; j < n; j++) tot += !F[i][j];
		return tot;
	}
	memset(dp, 0xc1, sizeof(dp));
	vector<vector<int>> to(n, vector<int>(n, -1));
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) if (!F[i][j]) {
			int r = j;
			while (r+1 < n && !F[i][r+1]) r++;
			for (int k = j; k <= r; k++) to[i][k] = r;
			dp[i][i][j][r] = r-j+1;
			j = r;
		}
	}
	for (int len = 1; len < n; len++) {
		for (int i = 0; i+len-1 < n; i++) {
			int j = i+len-1;
			for (int l = 0; l < n; l++) {
				for (int r = l; r < n; r++) if (dp[i][j][l][r] > 0) {
					if (i) {
						for (int z = l; z <= r; z++) if (~to[i-1][z]) {
							int new_r = min(to[i-1][z], r);
							ckmax(dp[i-1][j][z][new_r], dp[i][j][l][r] + new_r - z + 1);
						}
					}
					if (j+1 < n) {
						for (int z = l; z <= r; z++) if (~to[j+1][z]) {
							int new_r = min(to[j+1][z], r);
							ckmax(dp[i][j+1][z][new_r], dp[i][j][l][r] + new_r - z + 1);
						}
					}
				}
			}
		}
	}
	int ans = 0;
	for (int i = 0; i < n; i++) for (int j = i; j < n; j++) for (int k = 0; k < n; k++) for (int l = k; l < n; l++) ckmax(ans, dp[i][j][k][l]);
	return ans;
}

• Subtask 0: 0 / 0
• Subtask 1: 6 / 6
• Subtask 2: 8 / 8
• Subtask 3: 22 / 22
• Subtask 4: 18 / 18
• Subtask 5: 4 / 16
• Subtask 6: 7.5 / 30