Submission #50925

# Submission time Handle Problem Language Result Execution time Memory
50925 2018-06-14T22:56:18 Z Mamnoon_Siam Simurgh (IOI17_simurgh) C++17
30 / 100
836 ms 14812 KB
#pragma GCC optimize("Ofast,unroll-loops,no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")

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

#define debug(s) cerr<< #s <<" = "<< s <<endl
#define all(v) (v).begin(), (v).end()
#define KeepUnique(v) (v).erase( unique(all(v)), v.end() )
#define MEMSET(a,val) memset(a, val, sizeof a)
#define PB push_back
#define endl '\n'

inline int myrand(int l, int r) {
	int ret = rand(); ret <<= 15; ret ^= rand();
	if(ret < 0) ret = -ret; ret %= (r-l+1); ret += l;
	return ret;
}
template <typename F, typename S>
ostream& operator << (ostream& os, const pair< F, S>& p) {
    return os<<"(" <<p.first<<", "<<p.second<<")"; }

typedef pair<int, int> ii;
template<typename T> using min_pq =
	priority_queue<T, vector<T>, greater<T> >;

//int dx[] = {-1, +0, +1, +0};
//int dy[] = {+0, +1, +0, -1};

struct edge {
	int v, id;
	edge() {v = 0, id = 0;};
	edge(int v, int id) {
		this -> v = v;
		this -> id = id;
	}
	bool operator < (const edge &tmp) const {
		return ii(v, id) < ii(tmp.v, tmp.id);
	}
};

const int maxn = 505;

int n, m;
set<edge> g[505];
vector<ii> edges;
int pid[maxn];
bool vis[maxn], ok[maxn * maxn];
int edge_id[maxn][maxn];
int mx;
int head, tail;
bool col[maxn][maxn];
int lvl[maxn];
set<int> rem;

int par[maxn], sz[maxn];
int find(int u) {
	return par[u] == u ? u : par[u] = find(par[u]);
}
void unite(int u, int v) {
	col[u][v] = col[v][u] = 1;

	u = find(u), v = find(v);
	if(u == v) return ;
	if(sz[u] > sz[v]) swap(u, v);
	par[u] = v, sz[v] += sz[u];
}

void delete_edge(int id) {
	int u = edges[id].first, v = edges[id].second;
	g[u].erase(edge(v, id));
	g[v].erase(edge(u, id));
	ok[id] = 0;
	rem.erase(id);
}

void dfs(int u, int pe, int l) {
	lvl[u] = l;
	vis[u] = 1;
	pid[u] = pe;
	for(edge v : g[u]) {
		if(v.id == pe) continue;
		if(!vis[v.v]) {
			dfs(v.v, v.id, l+1);
		} else if(mx < lvl[u] - lvl[v.v]) {
			mx = lvl[u] - lvl[v.v];
			tail = u, head = v.v;
		}
	}
}

void round() {
	MEMSET(vis, 0);
	mx = 0;

	// do dfs, head, tail
	dfs(0, -1, 0);

	// extract tree edges
	vector<int> tree_edges;
	for(int i = 1; i < n; i++) {
		tree_edges.push_back(pid[i]);
	}

	// extract all edges which are cycle and tree edges
	vector<int> on_path;
	int temp_tail = tail;
	while(true) {
		on_path.push_back(pid[tail]);
		int u = edges[pid[tail]].first, v = edges[pid[tail]].second;
		tail ^= u ^ v;
		if(tail == head) break;
	} tail = temp_tail;

	// the back edge
	int bid = edge_id[head][tail];

	// extract differences
	vector<int> ask(on_path.size());
	int prev = count_common_roads(tree_edges);
	for(int i = 0; i < on_path.size(); i++) {
		vector<int> temp = tree_edges;
		temp.erase(find(all(temp), on_path[i]));
		temp.push_back(bid);
		int now = count_common_roads(temp);
		ask[i] = now - prev;
	}

	// identify the colours
	int allz = 1, mode_val;
	for(int i = 0; i < on_path.size(); i++) {
		if(ask[i] != 0) allz = 0, mode_val = ask[i];
	}
	if(allz) {
		for(int b : on_path) {
			delete_edge(b);
		} delete_edge(bid);
		// all are white
	} else {
		if(mode_val == -1) {
			delete_edge(bid);
			// which on_path are -1, they are black
			for(int i = 0; i < on_path.size(); i++) {
				int u = edges[on_path[i]].first, v = edges[on_path[i]].second;
				if(ask[i] == -1) {
					unite(u, v);
				}
			}
		} else {
			for(int i = 0; i < on_path.size(); i++) {
				if(ask[i] == +1) {
					delete_edge(on_path[i]);
				} // those who are +1 are white
			} // bid is black
			int u = edges[bid].first, v = edges[bid].second;
			unite(u, v);
		}
	}
}

int live_edges() {
	int ret = 0;
	for(int i = 0; i < edges.size(); i++) {
		ret += ok[i];
	} return ret;
}

vector<int> find_roads(int N, vector<int> U, vector<int> V) {
	n = N;
	for(int i = 0; i < U.size(); i++) {
		g[U[i]].insert(edge(V[i], i));
		g[V[i]].insert(edge(U[i], i));
		edges.push_back(ii(U[i], V[i]));
		edge_id[U[i]][V[i]] = i;
		edge_id[V[i]][U[i]] = i;
	}
	for(int i = 0; i < n; i++) {
		par[i] = i, sz[i] = 1;
	}
	for(int i = 0; i < U.size(); i++)
		ok[i] = 1, rem.insert(i);

	while(live_edges() >= n) {
		round();
		for(int i : rem) {
			int u = edges[i].first, v = edges[i].second;
			if(ok[i] and !col[u][v] and find(u) == find(v)) {
				delete_edge(i);
			}
		}
	}

	vector<int> ret;
	for(int i = 0; i < edges.size(); i++) {
		if(ok[i]) ret.push_back(i);
	} return ret;
}

Compilation message

simurgh.cpp: In function 'int myrand(int, int)':
simurgh.cpp:17:2: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  if(ret < 0) ret = -ret; ret %= (r-l+1); ret += l;
  ^~
simurgh.cpp:17:26: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  if(ret < 0) ret = -ret; ret %= (r-l+1); ret += l;
                          ^~~
simurgh.cpp: In function 'void round()':
simurgh.cpp:122:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < on_path.size(); i++) {
                 ~~^~~~~~~~~~~~~~~~
simurgh.cpp:132:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < on_path.size(); i++) {
                 ~~^~~~~~~~~~~~~~~~
simurgh.cpp:144:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int i = 0; i < on_path.size(); i++) {
                   ~~^~~~~~~~~~~~~~~~
simurgh.cpp:151:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int i = 0; i < on_path.size(); i++) {
                   ~~^~~~~~~~~~~~~~~~
simurgh.cpp: In function 'int live_edges()':
simurgh.cpp:164:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < edges.size(); i++) {
                 ~~^~~~~~~~~~~~~~
simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:171:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < U.size(); i++) {
                 ~~^~~~~~~~~~
simurgh.cpp:181:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < U.size(); i++)
                 ~~^~~~~~~~~~
simurgh.cpp:195:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < edges.size(); i++) {
                 ~~^~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB correct
2 Correct 2 ms 376 KB correct
3 Correct 2 ms 428 KB correct
4 Correct 2 ms 428 KB correct
5 Correct 2 ms 616 KB correct
6 Correct 2 ms 616 KB correct
7 Correct 2 ms 616 KB correct
8 Correct 2 ms 656 KB correct
9 Correct 2 ms 656 KB correct
10 Correct 2 ms 656 KB correct
11 Correct 2 ms 656 KB correct
12 Correct 2 ms 700 KB correct
13 Correct 3 ms 700 KB correct
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB correct
2 Correct 2 ms 376 KB correct
3 Correct 2 ms 428 KB correct
4 Correct 2 ms 428 KB correct
5 Correct 2 ms 616 KB correct
6 Correct 2 ms 616 KB correct
7 Correct 2 ms 616 KB correct
8 Correct 2 ms 656 KB correct
9 Correct 2 ms 656 KB correct
10 Correct 2 ms 656 KB correct
11 Correct 2 ms 656 KB correct
12 Correct 2 ms 700 KB correct
13 Correct 3 ms 700 KB correct
14 Correct 18 ms 892 KB correct
15 Correct 28 ms 892 KB correct
16 Correct 38 ms 892 KB correct
17 Correct 18 ms 892 KB correct
18 Correct 4 ms 892 KB correct
19 Correct 15 ms 948 KB correct
20 Correct 9 ms 948 KB correct
21 Correct 14 ms 1024 KB correct
22 Correct 8 ms 1024 KB correct
23 Correct 8 ms 1024 KB correct
24 Correct 6 ms 1024 KB correct
25 Correct 2 ms 1024 KB correct
26 Correct 7 ms 1024 KB correct
27 Correct 7 ms 1024 KB correct
28 Correct 4 ms 1024 KB correct
29 Correct 2 ms 1024 KB correct
30 Correct 6 ms 1024 KB correct
31 Correct 10 ms 1024 KB correct
32 Correct 8 ms 1024 KB correct
33 Correct 7 ms 1024 KB correct
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB correct
2 Correct 2 ms 376 KB correct
3 Correct 2 ms 428 KB correct
4 Correct 2 ms 428 KB correct
5 Correct 2 ms 616 KB correct
6 Correct 2 ms 616 KB correct
7 Correct 2 ms 616 KB correct
8 Correct 2 ms 656 KB correct
9 Correct 2 ms 656 KB correct
10 Correct 2 ms 656 KB correct
11 Correct 2 ms 656 KB correct
12 Correct 2 ms 700 KB correct
13 Correct 3 ms 700 KB correct
14 Correct 18 ms 892 KB correct
15 Correct 28 ms 892 KB correct
16 Correct 38 ms 892 KB correct
17 Correct 18 ms 892 KB correct
18 Correct 4 ms 892 KB correct
19 Correct 15 ms 948 KB correct
20 Correct 9 ms 948 KB correct
21 Correct 14 ms 1024 KB correct
22 Correct 8 ms 1024 KB correct
23 Correct 8 ms 1024 KB correct
24 Correct 6 ms 1024 KB correct
25 Correct 2 ms 1024 KB correct
26 Correct 7 ms 1024 KB correct
27 Correct 7 ms 1024 KB correct
28 Correct 4 ms 1024 KB correct
29 Correct 2 ms 1024 KB correct
30 Correct 6 ms 1024 KB correct
31 Correct 10 ms 1024 KB correct
32 Correct 8 ms 1024 KB correct
33 Correct 7 ms 1024 KB correct
34 Incorrect 738 ms 6052 KB WA in grader: NO
35 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 2 ms 6052 KB correct
2 Correct 2 ms 6052 KB correct
3 Incorrect 836 ms 14812 KB WA in grader: NO
4 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB correct
2 Correct 2 ms 376 KB correct
3 Correct 2 ms 428 KB correct
4 Correct 2 ms 428 KB correct
5 Correct 2 ms 616 KB correct
6 Correct 2 ms 616 KB correct
7 Correct 2 ms 616 KB correct
8 Correct 2 ms 656 KB correct
9 Correct 2 ms 656 KB correct
10 Correct 2 ms 656 KB correct
11 Correct 2 ms 656 KB correct
12 Correct 2 ms 700 KB correct
13 Correct 3 ms 700 KB correct
14 Correct 18 ms 892 KB correct
15 Correct 28 ms 892 KB correct
16 Correct 38 ms 892 KB correct
17 Correct 18 ms 892 KB correct
18 Correct 4 ms 892 KB correct
19 Correct 15 ms 948 KB correct
20 Correct 9 ms 948 KB correct
21 Correct 14 ms 1024 KB correct
22 Correct 8 ms 1024 KB correct
23 Correct 8 ms 1024 KB correct
24 Correct 6 ms 1024 KB correct
25 Correct 2 ms 1024 KB correct
26 Correct 7 ms 1024 KB correct
27 Correct 7 ms 1024 KB correct
28 Correct 4 ms 1024 KB correct
29 Correct 2 ms 1024 KB correct
30 Correct 6 ms 1024 KB correct
31 Correct 10 ms 1024 KB correct
32 Correct 8 ms 1024 KB correct
33 Correct 7 ms 1024 KB correct
34 Incorrect 738 ms 6052 KB WA in grader: NO
35 Halted 0 ms 0 KB -