Submission #875865

#	Time	Username	Problem	Language	Result	Execution time	Memory
875865		serifefedartar	Domino (COCI15_domino)	C++17	70 / 160	4167 ms	524288 KiB

domino

#include <bits/stdc++.h>
using namespace std;
 
#define fast ios::sync_with_stdio(0);cin.tie(0);
#define s second
#define f first
typedef long long ll;
const ll MOD = 998244353;
const ll LOGN = 20; 
const ll MAXN = 5e6 + 101;

struct Edge {
	int from, to, cost;
	char cap;
	Edge() { }
	Edge(int _from, int _to, int _cost, char _cap) : from(_from), to(_to), cost(_cost), cap(_cap) { }
}; 

struct Flow {
	vector<Edge> edges;
	vector<vector<int>> graph;
	vector<short> dist, from;
	int Q, source, terminal;
	Flow(int n) {
		Q = -1;
		graph = vector<vector<int>>(n + 10);
		dist = vector<short>(n + 10);
		from = vector<short>(n + 10);
	}
	void addEdge(int from, int to, int cost, int cap) {
		Q++;
		edges.push_back(Edge(from, to, cost, cap));
		graph[from].push_back(Q);
		Q++;
		edges.push_back(Edge(to, from, -cost, 0));
		graph[to].push_back(Q);
	}
	bool shortestPath() {
		for (int i = 0; i < dist.size(); i++)
			dist[i] = 10000;
		dist[source] = 0;
		priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>>> pq;
		pq.push({0, source});
		while (!pq.empty()) {
			int node = pq.top().s;
			int d = pq.top().f;
			pq.pop();
			for (auto u : graph[node]) {
				if (edges[u].cap && dist[edges[u].to] > edges[u].cost + d) {
					dist[edges[u].to] = edges[u].cost + d;
					from[edges[u].to] = u;
					pq.push({dist[edges[u].to], edges[u].to});
				}
			}
		}
		return (dist[terminal] != 10000);
	}
	ll minCost() {
		ll cost = 0;
		while (shortestPath()) {
			cost += dist[terminal];
			int now = terminal;

			while (now != source) {
				int edge_id = from[now];
				int from = edges[edge_id].from;
				now = from;
				edges[edge_id].cap--;
				edges[edge_id ^ 1].cap++;
			}
		}
		return cost;
	}
};

int grid[2005][2005];
int main() {
	fast
	int N, K;
	cin >> N >> K;

	ll ans = 0;
	for (int i = 0; i < N; i++) {
		for (int j = 1; j <= N; j++) {
			cin >> grid[i][j];
			ans += grid[i][j];
		}
	}

	Flow F = Flow(N * N + 10);
	F.addEdge(N * N + 2, 0, 0, K);
	for (int i = 0; i < N; i++) {
		for (int j = 1; j <= N; j++) {
			if ((i + 1 + j) % 2)
				F.addEdge(0, i * N + j, -grid[i][j], 1);
		}
	}
	for (int i = 0; i < N; i++) {
		for (int j = 1; j <= N; j++) {
			if ((i + 1 + j) % 2) {
				if (j != N)
					F.addEdge(i * N + j, i * N + j + 1, 0, 1);
				if (i != N - 1)
					F.addEdge(i * N + j, (i+1) * N + j, 0, 1);
				if (j != 1)
					F.addEdge(i * N + j, i * N + j - 1, 0, 1);
				if (i != 0)
					F.addEdge(i * N + j, (i-1) * N + j, 0, 1);
			}
		}
	}
	for (int i = 0; i < N; i++) {
		for (int j = 1; j <= N; j++) {
			if ((i + 1 + j) % 2 == 0)
				F.addEdge(i * N + j, N * N + 1, -grid[i][j], 1);
		}
	}
	F.source = N * N + 2, F.terminal = N * N + 1;

	ans += F.minCost();
	cout << ans << "\n";
}

Compilation message (stderr)

domino.cpp: In member function 'bool Flow::shortestPath()':
domino.cpp:39:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<short int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |   for (int i = 0; i < dist.size(); i++)
      |                   ~~^~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 0 / 10
• Subtask 4: 10 / 10
• Subtask 5: 0 / 10
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• Subtask 8: 10 / 10
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• Subtask 11: 10 / 10
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• Subtask 13: 10 / 10
• Subtask 14: 0 / 10
• Subtask 15: 10 / 10
• Subtask 16: 0 / 10