oj.uz

Submission #306481

# Submission time Handle Problem Language Result Execution time Memory
306481 2020-09-25T17:05:59 Z tengiz05 Dreaming (IOI13_dreaming) C++17
0 / 100
 126 ms 17016 KB 
#include "dreaming.h"
#include <bits/stdc++.h>
using namespace std;
int n;
const int N = 1e5+5;
bool used[N];
int depth[N];
int dp[N];
vector<pair<int, int>> edges[N];
vector<int> a[N];
// dfs for calculating dp. (dp[i] - maximum depth)
void dfs(int u, int p){
	used[u] = true;
	dp[u] = 0;
	a[u].push_back(0);a[u].push_back(0);
	for(auto X : edges[u]){
		int v = X.first;
		int cost = X.second;
		if(v == p)continue;
		dfs(v, u);
		dp[u] = max(dp[u], dp[v]+cost);
		a[u].push_back(dp[v]+cost);
	}
	sort(a[u].begin(), a[u].end());
	reverse(a[u].begin(), a[u].end());
}

//dfs for rerooting
int mn;
void dfs2(int u, int p, int T){
	int dpu = dp[u];
	for(auto X : edges[u]){
		int v = X.first;
		int cost = X.second;
		if(v == p)continue;
		int tmp = dp[v];
		if(dp[v]+cost == a[u][0])dp[u] = a[u][1];
		if(u != p)dp[u] = max(dp[u], dp[p] + T);
		dp[v] = max(dp[v], dp[u] + cost);
		mn = min(mn, dp[v]);
		dfs2(v, u, cost);
		dp[v] = tmp;
		dp[u] = dpu;
	}
}

//calculate best center for the tree
int calculate_center(int u){
	dfs(u, u);
	mn = dp[u];
	dfs2(u, u ,0);
	return mn;
}
int travelTime(int _N, int M, int L, int A[], int B[], int T[]) {
	n = _N;
	for(int i=0;i<M;i++){
		edges[A[i]].push_back({B[i], T[i]});
		edges[B[i]].push_back({A[i], T[i]});
	}
	vector<int> v;
	for(int i=0;i<n;i++){
		if(!used[i]){
			v.push_back(calculate_center(i));
		}
	}
	sort(v.begin(), v.end());
	reverse(v.begin(), v.end());
	if(v.size() == 0){
		return 0;
	}
	else if(v.size() == 1){
		return v[0];
	}else {
		return v[0]+v[1]+L;
	}
}

Subtask #1
0 / 14.0

# Verdict Execution time Memory Grader output
1 Incorrect 126 ms 17016 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 126 ms 17016 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 23.0

# Verdict Execution time Memory Grader output
1 Incorrect 126 ms 17016 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 55 ms 10996 KB Output is correct
2 Incorrect 63 ms 10996 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #5
0 / 12.0

# Verdict Execution time Memory Grader output
1 Incorrect 126 ms 17016 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #6
0 / 23.0

# Verdict Execution time Memory Grader output
1 Incorrect 126 ms 17016 KB Output isn't correct
2 Halted 0 ms 0 KB -