Submission #979737

#	Time	Username	Problem	Language	Result	Execution time	Memory
979737		c2zi6	Hexagonal Territory (APIO21_hexagon)	C++14	20 / 100	95 ms	197448 KiB

hexagon

#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
#define ff first
#define ss second
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define replr(i, a, b) for (int i = int(a); i <= int(b); ++i)
#define reprl(i, a, b) for (int i = int(a); i >= int(b); --i)
#define rep(i, n) for (int i = 0; i < int(n); ++i)
#define mkp(a, b) make_pair(a, b)
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef vector<int> VI;
typedef vector<PII> VPI;
typedef vector<VI> VVI;
typedef vector<VVI> VVVI;
typedef vector<VPI> VVPI;
typedef pair<ll, ll> PLL;
typedef vector<ll> VL;
typedef vector<PLL> VPL;
typedef vector<VL> VVL;
typedef vector<VVL> VVVL;
typedef vector<VPL> VVPL;
template<class T> T setmax(T& a, T b) {if (a < b) return a = b; return a;}
template<class T> T setmin(T& a, T b) {if (a < b) return a; return a = b;}
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
template<class T>
using indset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#include "hexagon.h"

const ll MOD = 1e9 + 7;

ll binpow(ll a, ll b) {
	if (b == 0) return 1;
	if (b & 1) return a*binpow(a, b-1) % MOD;
	ll ret = binpow(a, b/2);
	return ret*ret % MOD;
}
ll inv(ll x) {
	return binpow(x, MOD-2);
}
ll sum(ll n) {
	return n*(n+1) % MOD * inv(2) % MOD;
}
ll sumsq(ll n) {
	return n * (2*n+1) % MOD * (n+1) % MOD * inv(6) % MOD;
}

VPI harevan(int i, int j) {
	VPI ret;
	if (j & 1) {
		ret.pb({i-1, j});
		ret.pb({i-1, j+1});
		ret.pb({i, j+1});
		ret.pb({i+1, j});
		ret.pb({i, j-1});
		ret.pb({i-1, j-1});
	} else {
		ret.pb({i-1, j});
		ret.pb({i, j+1});
		ret.pb({i+1, j+1});
		ret.pb({i+1, j});
		ret.pb({i+1, j-1});
		ret.pb({i, j-1});
	}
	return ret;
}

int table[5000][5000];
int dist[5000][5000];

void dfs(int i, int j) {
	table[i][j] = 3;
	for (auto[vi, vj] : harevan(i, j)) if (table[vi][vj] == 2) {
		dfs(vi, vj);
	}
}

int draw_territory(int n, int A, int B, VI D, VI L) {
	if (n == 3) {
		ll x = L[0]+1;
		ll mas1 = sum(x) * A % MOD;
		ll mas2 = (sumsq(x) + MOD-sum(x))%MOD * B % MOD;
		return (mas1 + mas2) % MOD;
	}

	int ui = 2500, uj = 2500;
	rep(i, n) {
		int dir = D[i]-1;
		rep(j, L[i]) {
			auto[vi, vj] = harevan(ui, uj)[dir];
			table[ui][uj] = 1;
			ui = vi;
			uj = vj;
		}
	}

	int lmi, lmj = 1e9;
	replr(i, 1, 4998) replr(j, 1, 4998) if (table[i][j] == 1) {
		for (auto[vi, vj] : harevan(i, j)) {
			if (table[vi][vj] == 1) continue;
			if (vj < lmj) {
				lmi = vi;
				lmj = vj;
			}
			table[vi][vj] = 2;
		}
	}
	dfs(lmi, lmj);
	replr(i, 1, 4998) replr(j, 1, 4998) if (table[i][j] < 3) table[i][j] = 0;
	replr(i, 0, 4999) replr(j, 0, 4999) dist[i][j] = 2e9;
	queue<PII> q;
	q.push({2500, 2500});
	dist[2500][2500] = 0;
	VI ans{0};
	while (q.size()) {
		auto[ui, uj] = q.front();
		q.pop();
		for (auto[vi, vj] : harevan(ui, uj)) if (table[vi][vj] == 0 && dist[vi][vj] == 2e9) {
			dist[vi][vj] = dist[ui][uj]+1;

			ans.pb(dist[vi][vj]);

			q.push({vi, vj});
		}
	}

	/* for (int x : ans) cout << x << " "; cout << endl; */
	/* replr(i, 2500-6, 2500+6) { */
	/* 	replr(j, 2500-2, 2500+10) cout << table[i][j] << " "; */
	/* 	cout << endl; */
	/* } */

	ll ret = 0;
	for (int x : ans) {
		ll cur = (A + 1ll * x * B) % MOD;
		ret += cur;
		ret %= MOD;
	}
	return ret;
}

Compilation message (stderr)

hexagon.cpp: In function 'void dfs(int, int)':
hexagon.cpp:77:11: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   77 |  for (auto[vi, vj] : harevan(i, j)) if (table[vi][vj] == 2) {
      |           ^
hexagon.cpp: In function 'int draw_territory(int, int, int, VI, VI)':
hexagon.cpp:94:8: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   94 |    auto[vi, vj] = harevan(ui, uj)[dir];
      |        ^
hexagon.cpp:103:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  103 |   for (auto[vi, vj] : harevan(i, j)) {
      |            ^
hexagon.cpp:120:7: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  120 |   auto[ui, uj] = q.front();
      |       ^
hexagon.cpp:122:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  122 |   for (auto[vi, vj] : harevan(ui, uj)) if (table[vi][vj] == 0 && dist[vi][vj] == 2e9) {
      |            ^
hexagon.cpp:112:5: warning: 'lmi' may be used uninitialized in this function [-Wmaybe-uninitialized]
  112 |  dfs(lmi, lmj);
      |  ~~~^~~~~~~~~~

• Subtask 1: 3 / 3
• Subtask 2: 6 / 6
• Subtask 3: 11 / 11
• Subtask 4: 0 / 12
• Subtask 5: 0 / 15
• Subtask 6: 0 / 19
• Subtask 7: 0 / 18
• Subtask 8: 0 / 16