Submission #51838

#	Time	Username	Problem	Language	Result	Execution time	Memory
51838		ernestvw	Simurgh (IOI17_simurgh)	C++11	0 / 100	3 ms	888 KiB

simurgh

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

//int count_common_roads(vector<int> r);

struct Arc {
	int u, v, i;
};

int nbNodes(0), nbArcs(0);
int parent[501];
Arc arcs[501*250];
vector<Arc> adj[501];
int depth[501];
int indice[501][501];
bool vu[501];
int memo[501][501];//-1 if not calc., 0 if same, 1 if x+1, 2 if x-1
set<int> golden;
int oldValue(-1);

const int ROYAL = 500*250+2;
const int NOT_ROYAL = 500*250+1;
int repr[501*250];
int find(int x) {
	return x == repr[x] ? x : (repr[x] = find(repr[x]));
}
void merge(int x, int y) {
	repr[find(x)] = find(y);
}

int query() {
	vector<int>r;
	for(int i:golden)r.push_back(i);
	return oldValue = count_common_roads(r);
}

void findParent(int u, int p, int d) {
	if(vu[u]) return;
	vu[u] = 1;
	parent[u] = p;
	depth[u] = d;
	for(Arc a : adj[u])
		if(a.v != p)
			findParent(a.v, u, d+1);
}

vector<int> cur;
vector<int> ans;
bool ffff=0;

void dfs(int u, int p, int cible) {
	if(u == cible) {
		ans = cur;
		ffff=1;
	}
	if(ffff)return;
	for(Arc a : adj[u]) {
		if(!golden.count(a.i) or a.v == p) continue;
		cur.push_back(a.i);
		dfs(a.v, u, cible);
		cur.pop_back();
	}
}

vector<int> edges(int u, int v) {
	dfs(u, -1, v);
	return ans;
}

void buildTree() {
	for(int node = 0; node < nbNodes; node++)
		if(parent[node] != -1)
			golden.insert(indice[node][parent[node]]);
}

vector<int> find_roads(int n, vector<int> u, vector<int> v) {
	nbNodes = n;
	nbArcs = (int)u.size();
	for(int iArc = 0; iArc < nbArcs; iArc++) {
		arcs[iArc].u = u[iArc];
		arcs[iArc].v = v[iArc];
		arcs[iArc].i = iArc;
		adj[u[iArc]].push_back({u[iArc], v[iArc], iArc});
		adj[v[iArc]].push_back({v[iArc], u[iArc], iArc});
		indice[u[iArc]][v[iArc]] = indice[v[iArc]][u[iArc]] = iArc;
	}
	for(int i = 0; i < n; i++) vu[i] = 0;
	findParent(0, -1, 0);
	for(int i = 0; i < 501*250; i++) repr[i] = i;
	buildTree();
	query();
	vector<int> sol;
	for(int iA = 0; iA < nbArcs; iA++) {
		Arc a = arcs[iA];
		if(oldValue == n - 1) break;
		if(golden.count(a.i)) continue;
		vector<int> arcsPossibles = edges(a.u, a.v);
//		cout << a.i << ":\n";
		for(int i : arcsPossibles) {
//			cout << " " << i << ":\n";
			int old = oldValue;
			golden.erase(i);
			golden.insert(a.i);
			query();
//			cout << "\t" << old << " " << oldValue << endl;
			if(oldValue == old) {
				merge(i, a.i);
				golden.insert(i);
				golden.erase(a.i);
			}
			else if(oldValue > old) {
				merge(NOT_ROYAL, i);
				merge(ROYAL, a.i);
				break;
			}
			else {
				golden.erase(a.i);
				golden.insert(i);
				merge(ROYAL, i);
				merge(NOT_ROYAL, a.i);
				oldValue = old;
				break;
			}
		}
	}
	for(int i = 0; i < nbArcs; i++)if(find(i) == find(ROYAL))cout << i << " ";cout<<endl;
	for(int i : golden) sol.push_back(i);
	return sol;
}

Compilation message (stderr)

simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:127:2: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
  for(int i = 0; i < nbArcs; i++)if(find(i) == find(ROYAL))cout << i << " ";cout<<endl;
  ^~~
simurgh.cpp:127:76: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
  for(int i = 0; i < nbArcs; i++)if(find(i) == find(ROYAL))cout << i << " ";cout<<endl;
                                                                            ^~~~

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