Submission #417492

#	Time	Username	Problem	Language	Result	Execution time	Memory
417492		iulia13	Dreaming (IOI13_dreaming)	C++14	100 / 100	136 ms	18620 KiB

dreaming

#include <bits/stdc++.h>
#include "dreaming.h"
using namespace std;
const int N = 1e5 + 5;
struct ura{
    int x, c;
};
vector <ura> g[N];
int maxi = 2e9, dp[N], dp2[N], dp_up[N];
int lover[N];
int viz[N];
vector <int> A;
void dfs(int nod, int dad = -1)
{
    viz[nod] = 1;
    for (auto son : g[nod])
    {
        if (son.x == dad)
            continue;
        dfs(son.x, nod);
        if (dp[nod] < dp[son.x] + son.c)
        {
            dp2[nod] = dp[nod];
            dp[nod] = dp[son.x] + son.c;
        }
        else
            dp2[nod] = max(dp2[nod], dp[son.x] + son.c);
    }
}
void dfs2(int nod, int dad = -1)
{
    for (auto son : g[nod])
    {
        if (son.x == dad)
            continue;
        int c = dp[nod];
        if (c == dp[son.x] + son.c)
            c = dp2[nod];
        dp_up[son.x] = max(dp_up[nod], c) + son.c;
        dfs2(son.x, nod);
    }
    lover[nod] = max(dp_up[nod], dp[nod]);
    maxi = min(lover[nod], maxi);
}
int dist[N], bebe = -1, maxim;
void dfs_diametru(int nod, int dad = -1)
{
    for (auto son : g[nod])
    {
        if (son.x == dad)
            continue;
        dist[son.x] = dist[nod] + son.c;
        if (dist[son.x] > maxim)
        {
            maxim = dist[son.x];
            bebe = son.x;
        }
        dfs_diametru(son.x, nod);
    }
}
void dfs_clear(int nod, int dad = -1)
{
    dist[nod] = 0;
    for (auto son : g[nod])
    {
        if (son.x == dad)
            continue;
        dfs_clear(son.x, nod);
    }
}
int travelTime(int n, int m, int l, int a[], int b[], int t[])
{
    int i, j;
    for (i = 0; i < m; i++)
    {
        g[a[i]].push_back({b[i], t[i]});
        g[b[i]].push_back({a[i], t[i]});
    }
    int c = 0;
    for (i = 0; i < n; i++)
    {
        if (viz[i])
            continue;
        maxi = 2e9;
        dfs(i);
        dfs2(i);
        maxim = 0;
        A.push_back(maxi);
        bebe = -1;
        dfs_diametru(i);
        dfs_clear(i);
        if (bebe == -1)
            continue;
        dfs_diametru(bebe);
        c = max(c, dist[bebe]);
    }
    if (A.size() == 1)
        return max(c, A[0]);
    sort(A.begin(), A.end());
    reverse(A.begin(), A.end());
    c = max(c, A[0] + A[1] + l);
    if (A.size() == 2)
        return c;
    else
        return max(c, A[1] + A[2] + 2 * l);
}

Compilation message (stderr)

dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:73:12: warning: unused variable 'j' [-Wunused-variable]
   73 |     int i, j;
      |            ^

• Subtask 1: 14 / 14
• Subtask 2: 10 / 10
• Subtask 3: 23 / 23
• Subtask 4: 18 / 18
• Subtask 5: 12 / 12
• Subtask 6: 23 / 23