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Submission #296601

# Submission time Handle Problem Language Result Execution time Memory
296601 2020-09-10T17:00:54 Z williamMBDK Dreaming (IOI13_dreaming) C++14
18 / 100
 151 ms 21996 KB 
#include<bits/stdc++.h>
#include "dreaming.h"
#define int long long
using namespace std;
int N, M;
vector<vector<pair<int,int>>> adj (1e5), distances (1e5);
vector<int> mxdist (1e5), mxinnerdist(1e5);
vector<vector<int>> getcomps(){
	vector<bool> v (N);
	vector<vector<int>> res;
	for(int i = 0; i < N; i++){
		if(!v[i]){
			queue<int> q;
			q.push(i);
			res.push_back({});
			while(!q.empty()){
				int curr = q.front(); q.pop();
				if(v[curr]) continue;
				v[curr] = 1;
				res[res.size() - 1].push_back(curr);
				for(auto e : adj[curr]) q.push(e.first);
			}
		}
	}
	return res;
}
int dfs1(int node, int p){
	for(int i = 0; i < adj[node].size(); i++){
		if(adj[node][i].first == p) continue;
		distances[node][i].first = dfs1(adj[node][i].first, node) + adj[node][i].second;
		distances[node][i].second = i;
	}
	sort(distances[node].rbegin(), distances[node].rend());
	if(distances[node].size() < 2) return 0; // right?
	return distances[node][0].first;
}
void dfs2(int node, int p, int mxp){
	if(p == -1){
		if(adj[node].size() > 0) mxdist[node] = distances[node][0].first;
		else mxdist[node] = 0;
		if(adj[node].size() >= 2){
			mxinnerdist[node] = distances[node][0].first + distances[node][1].first;
		}else if(adj[node].size() == 1){
			mxinnerdist[node] = distances[node][0].first;
		}
	}else if(adj[node].size() == 1){
		mxdist[node] = mxp;	
		mxinnerdist[node] = mxp;
	}else{
		mxdist[node] = max(mxp, distances[node][0].first); // right?
		mxinnerdist[node] = mxp + distances[node][0].first;
		if(adj[node].size() > 2){
			mxinnerdist[node] = max(mxinnerdist[node], distances[node][0].first + distances[node][1].first);
		}
	}
	// cout << mxdist[node] << " " << node << endl;
	for(int i = 0; i < adj[node].size(); i++){
		if(adj[node][i].first == p) continue;
		int t = mxp;
		if(distances[node][0].second == i){
			if(distances[node].size() >= 3) t = max(t, distances[node][1].first);
		}else{
			t = max(t, distances[node][0].first); //right?
		}
		t += adj[node][i].second;
		dfs2(adj[node][i].first, node, t);
	}
}
signed travelTime(signed _N, signed _M, signed L, signed A[], signed B[], signed T[]) {
	N = _N;
	M = _M;
	for(int i = 0; i < M; i++){
		adj[A[i]].push_back({B[i],T[i]});
		adj[B[i]].push_back({A[i],T[i]});
		distances[A[i]].push_back({-1,-1});
		distances[B[i]].push_back({-1,-1});
	}
	vector<vector<int>> components = getcomps();
	int C = components.size();
	vector<int> compdists (C, INT_MAX);
	int res = 0;
	for(int i = 0; i < C; i++){
		// cout << "root" << components[i][0] << endl;
		dfs1(components[i][0], -1);
		dfs2(components[i][0], -1, 0);
		for(int j = 0; j < components[i].size(); j++){
			compdists[i] = min(compdists[i], mxdist[components[i][j]]);
			res = max(res, mxinnerdist[components[i][j]]);
		}
	}
	sort(compdists.rbegin(), compdists.rend());
	if(C == 1){
		return res;
	}else if(C == 2){
		return max(L + compdists[0] + compdists[1], res);
	}else{
		return max(res, max(L + compdists[0] + compdists[1], 2 * L + compdists[1] + compdists[2]));
	}
}

Compilation message

dreaming.cpp: In function 'long long int dfs1(long long int, long long int)':
dreaming.cpp:28:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |  for(int i = 0; i < adj[node].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~~~
dreaming.cpp: In function 'void dfs2(long long int, long long int, long long int)':
dreaming.cpp:57:19: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   57 |  for(int i = 0; i < adj[node].size(); i++){
      |                 ~~^~~~~~~~~~~~~~~~~~
dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:86:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   86 |   for(int j = 0; j < components[i].size(); j++){
      |                  ~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 151 ms 21488 KB Output is correct
2 Correct 115 ms 21996 KB Output is correct
3 Correct 69 ms 18452 KB Output is correct
4 Correct 15 ms 8960 KB Output is correct
5 Correct 15 ms 8320 KB Output is correct
6 Correct 26 ms 10356 KB Output is correct
7 Incorrect 5 ms 6656 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 151 ms 21488 KB Output is correct
2 Correct 115 ms 21996 KB Output is correct
3 Correct 69 ms 18452 KB Output is correct
4 Correct 15 ms 8960 KB Output is correct
5 Correct 15 ms 8320 KB Output is correct
6 Correct 26 ms 10356 KB Output is correct
7 Incorrect 5 ms 6656 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #3
0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 151 ms 21488 KB Output is correct
2 Correct 115 ms 21996 KB Output is correct
3 Correct 69 ms 18452 KB Output is correct
4 Correct 15 ms 8960 KB Output is correct
5 Correct 15 ms 8320 KB Output is correct
6 Correct 26 ms 10356 KB Output is correct
7 Incorrect 5 ms 6656 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #4
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 69 ms 15148 KB Output is correct
2 Correct 92 ms 15276 KB Output is correct
3 Correct 68 ms 15172 KB Output is correct
4 Correct 76 ms 15288 KB Output is correct
5 Correct 69 ms 15148 KB Output is correct
6 Correct 93 ms 16696 KB Output is correct
7 Correct 88 ms 15404 KB Output is correct
8 Correct 79 ms 14860 KB Output is correct
9 Correct 73 ms 14764 KB Output is correct
10 Correct 95 ms 15276 KB Output is correct
11 Correct 5 ms 6656 KB Output is correct
12 Correct 30 ms 12848 KB Output is correct
13 Correct 28 ms 12972 KB Output is correct
14 Correct 29 ms 12968 KB Output is correct
15 Correct 29 ms 12976 KB Output is correct
16 Correct 30 ms 12952 KB Output is correct
17 Correct 29 ms 12840 KB Output is correct
18 Correct 29 ms 12968 KB Output is correct
19 Correct 27 ms 12968 KB Output is correct
20 Correct 5 ms 6656 KB Output is correct
21 Correct 5 ms 6656 KB Output is correct
22 Correct 6 ms 6836 KB Output is correct
23 Correct 32 ms 12968 KB Output is correct

Subtask #5
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 151 ms 21488 KB Output is correct
2 Correct 115 ms 21996 KB Output is correct
3 Correct 69 ms 18452 KB Output is correct
4 Correct 15 ms 8960 KB Output is correct
5 Correct 15 ms 8320 KB Output is correct
6 Correct 26 ms 10356 KB Output is correct
7 Incorrect 5 ms 6656 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #6
0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 151 ms 21488 KB Output is correct
2 Correct 115 ms 21996 KB Output is correct
3 Correct 69 ms 18452 KB Output is correct
4 Correct 15 ms 8960 KB Output is correct
5 Correct 15 ms 8320 KB Output is correct
6 Correct 26 ms 10356 KB Output is correct
7 Incorrect 5 ms 6656 KB Output isn't correct
8 Halted 0 ms 0 KB -