Submission #1242156

#	Time	Username	Problem	Language	Result	Execution time	Memory
1242156		AmirAli_H1	Soccer Stadium (IOI23_soccer)	C++17	77.50 / 100	331 ms	47596 KiB

soccer

// In the name of Allah

#include <bits/stdc++.h>
#include "soccer.h"
using namespace std;

typedef		long long int			ll;
typedef		long double				ld;
typedef		pair<int, int>			pii;
typedef		pair<ll, ll>			pll;
typedef		complex<ld>				cld;

#define		all(x)					(x).begin(),(x).end()
#define		len(x)					((ll) (x).size())
#define		F						first
#define		S						second
#define		pb						push_back
#define		sep						' '
#define		endl					'\n'
#define		Mp						make_pair
#define		kill(x)					cout << x << '\n', exit(0)
#define		set_dec(x)				cout << fixed << setprecision(x);
#define		file_io(x,y)			freopen(x, "r", stdin); freopen(y, "w", stdout);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int maxn = 2000 + 4;

int n; int A[maxn][maxn];
vector<pair<int, pii>> lsx;
int ind1[maxn][maxn], ind2[maxn][maxn];
pii valx[maxn][maxn]; int dp[maxn][maxn];

int solver() {
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (A[i][j] == 1) {
				return (n * n) - (min(i + 1, n - i) * min(j + 1, n - j));
			}
		}
	}
	return n * n;
}

int solvex() {
	int sm = 0;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (A[i][j] == 0) sm++;
		}
	}
	int lx = n, rx = -1;
	for (int i = 0; i < n; i++) {
		int jx = 0, tx = 0;
		for (int j = 0; j < n; j++) {
			if (A[i][j] != A[i][jx]) {
				if (A[i][jx] == 0) {
					lsx.pb(Mp(i, Mp(jx, j))); tx++;
					lx = min(lx, i); rx = max(rx, i);
				}
				jx = j;
			}
		}
		if (A[i][jx] == 0) {
			lsx.pb(Mp(i, Mp(jx, n))); tx++;
			lx = min(lx, i); rx = max(rx, i);
		}
		if (tx >= 2) return 0;
	}
	if (rx - lx + 1 != len(lsx)) return 0;
	for (int i = 0; i < len(lsx); i++) {
		int i1 = i - 1, i2 = i + 1;
		int lx = lsx[i].S.F, rx = lsx[i].S.S;
		bool flag = 1;
		for (int j = 0; j < len(lsx) - 1; j++) {
			if (i1 < 0) {
				int l2 = lsx[i2].S.F, r2 = lsx[i2].S.S;
				if (l2 < lx || r2 > rx) {
					flag = 0;
					break;
				}
				lx = l2; rx = r2; i2++;
			}
			else if (i2 >= len(lsx)) {
				int l1 = lsx[i1].S.F, r1 = lsx[i1].S.S;
				if (l1 < lx || r1 > rx) {
					flag = 0;
					break;
				}
				lx = l1; rx = r1; i1--;
			}
			else {
				int l1 = lsx[i1].S.F, r1 = lsx[i1].S.S;
				int l2 = lsx[i2].S.F, r2 = lsx[i2].S.S;
				if (r1 - l1 + 1 >= r2 - l2 + 1) {
					if (l1 < lx || r1 > rx) {
						flag = 0;
						break;
					}
					lx = l1; rx = r1; i1--;
				}
				else {
					if (l2 < lx || r2 > rx) {
						flag = 0;
						break;
					}
					lx = l2; rx = r2; i2++;
				}
			}
		}
		if (flag) return sm;
	}
	return 0;
}

int biggest_stadium(int N, vector<vector<int>> F) {
	n = N; int sm = 0;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			A[i][j] = F[i][j];
			if (A[i][j] == 0) sm++;
		}
	}
	if (sm == n * n) return sm;
	else if (sm == n * n - 1) return solver();
	int x = solvex(); lsx.clear();
	if (x != 0 || n > 500) return x;
	for (int i = 0; i < n; i++) {
		for (int j = 0; j < n; j++) {
			if (A[i][j] == 1) ind1[i][j] = j + 1;
			else if (j - 1 >= 0) ind1[i][j] = ind1[i][j - 1];
			else ind1[i][j] = j;
		}
		for (int j = n - 1; j >= 0; j--) {
			if (A[i][j] == 1) ind2[i][j] = j - 1;
			else if (j + 1 < n) ind2[i][j] = ind2[i][j + 1];
			else ind2[i][j] = j;
		}
	}
	int ans = 0;
	for (int j = 0; j < n; j++) {
		for (int ln = 1; ln <= n; ln++) {
			for (int l = 0, r = ln; r <= n; l++, r++) {
				if (ln == 1) {
					valx[l][r] = Mp(ind1[l][j], ind2[l][j]);
					if (valx[l][r].F <= valx[l][r].S) dp[l][r] = (valx[l][r].S - valx[l][r].F + 1);
					else dp[l][r] = 0;
				}
				else {
					valx[l][r] = Mp(max(ind1[l][j], valx[l + 1][r].F), min(ind2[l][j], valx[l + 1][r].S));
					if (valx[l][r].F <= valx[l][r].S) dp[l][r] = max(dp[l + 1][r], dp[l][r - 1]) + (valx[l][r].S - valx[l][r].F + 1);
					else dp[l][r] = 0;
				}
				ans = max(ans, dp[l][r]);
			}
		}
	}
	return ans;
}

• 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: 7.5 / 30