Submission #834746

#	Time	Username	Problem	Language	Result	Execution time	Memory
834746		Josia	Simurgh (IOI17_simurgh)	C++17	51 / 100	278 ms	3956 KiB

simurgh

#include "simurgh.h"
#include <bits/stdc++.h>

using namespace std;





int query(set<int> x) {
	vector<int> edges;
	for (int i: x) edges.push_back(i);
	return count_common_roads(edges);
}



int n, m;

vector<vector<int>> graphList;
vector<vector<int>> graphMatrix;
vector<vector<int>> knownEdges;


struct solve {
	vector<int> vis;
	set<int> usedEdges;

	void dfs(int v, int p, int forbidden, int col) {
		if (vis[v]!=-1) return;
		vis[v] = col;

		if (p!=-1) {
			usedEdges.insert(graphMatrix[v][p]);
		}

		for (int u: graphList[v]) {
			if (u == forbidden) continue;
			dfs(u, v, forbidden, col);
		}
	}


	void start(int v) {
		vis.assign(n, -1);
		usedEdges.clear();
		int col = 0;
		vector<vector<int>> colors;
		for (int u: graphList[v]) {
			if (vis[u]==-1) {
				dfs(u, -1, v, col);
				col++;
				colors.push_back({});
			}

			colors[vis[u]].push_back(u);
		}

		for (auto i: colors) usedEdges.insert(graphMatrix[v][i[0]]);

		for (auto i: colors) {
			vector<int> vals;
			usedEdges.erase(graphMatrix[v][i[0]]);
			int hi = -1;
			for (int j: i) {
				if (knownEdges[v][j] != -1 && hi == -1) {
					usedEdges.insert(graphMatrix[v][j]);
					vals.push_back(query(usedEdges));
					usedEdges.erase(graphMatrix[v][j]);
					if (knownEdges[v][j] == 1) hi = vals.back();
					if (knownEdges[v][j] == 0) hi = vals.back()+1;
					continue;
				}
				if (knownEdges[v][j] != -1 && hi != -1) {
					if (knownEdges[v][j] == 1) vals.push_back(hi);
					if (knownEdges[v][j] == 0) vals.push_back(hi-1);
					continue;
				}
				usedEdges.insert(graphMatrix[v][j]);
				vals.push_back(query(usedEdges));
				usedEdges.erase(graphMatrix[v][j]);
			}
			usedEdges.insert(graphMatrix[v][i[0]]);
			if (hi == -1) hi = *max_element(vals.begin(), vals.end());

			for (int j = 0; j<(int)i.size(); j++) {
				if (vals[j] == hi) {
					knownEdges[i[j]][v] = 1;
					knownEdges[v][i[j]] = 1;
				}
				else {
					knownEdges[i[j]][v] = 0;
					knownEdges[v][i[j]] = 0;
				}
			}
		}
	}


	vector<int> output;
	solve() {
		for (int i = 0; i<n; i++) {
			start(i);
		}
		output.clear();

		for (int i = 0; i<n; i++) {
			for (int j = i+1; j<n; j++) {
				if (knownEdges[i][j]==0) continue;
				if (knownEdges[i][j]==-1) continue;
				// assert(knownEdges[i][j]==1);

				output.push_back(graphMatrix[i][j]);
			}
		}
	}
};



vector<int> find_roads(int _n, vector<int> u, vector<int> v) {
	n = _n;
	m = u.size();
	graphList.assign(n, vector<int>());
	graphMatrix.assign(n, vector<int>(n, -1));
	knownEdges.assign(n, vector<int>(n, -1));

	for (int i = 0; i<m; i++) {
		graphList[u[i]].push_back(v[i]);
		graphList[v[i]].push_back(u[i]);

		graphMatrix[u[i]][v[i]] = i;
		graphMatrix[v[i]][u[i]] = i;
	}

	solve sol;

	return sol.output;
}

• Subtask 1: 13 / 13
• Subtask 2: 17 / 17
• Subtask 3: 21 / 21
• Subtask 4: 0 / 19
• Subtask 5: 0 / 30