Submission #468928

#	Time	Username	Problem	Language	Result	Execution time	Memory
468928		Soumya1	Dreaming (IOI13_dreaming)	C++14	100 / 100	113 ms	18620 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>
using namespace std;
const int mxN = 1e5;
vector<pair<int, int>> ad[mxN];
bool vis[mxN];
int dp[mxN][2];
int mn = 1e9 + 5;
int ans = 0;
void dfs(int node) {
  vis[node] = true;
  for (auto [child, w] : ad[node]) {
    if (vis[child]) continue;
    dfs(child);
    if (dp[child][1] + w >= dp[node][1]) {
      dp[node][0] = dp[node][1];
      dp[node][1] = dp[child][1] + w;
    } else if (dp[child][1] + w > dp[node][0]) {
      dp[node][0] = dp[child][1] + w;
    }
  }
  ans = max(ans, dp[node][1] + dp[node][0]);
}
void dfs1(int node, int par, int cur) {
  mn = min(mn, max(cur, dp[node][1]));
  for (auto [child, w] : ad[node]) {
    if (child == par) continue;
    dfs1(child, node, max(cur, (dp[node][1] == dp[child][1] + w ? dp[node][0] : dp[node][1])) + w);
  } 
}
int travelTime(int n, int m, int l, int a[], int b[], int t[]) {
  for (int i = 0; i < m; i++) {
    ad[a[i]].push_back({b[i], t[i]});
    ad[b[i]].push_back({a[i], t[i]});
  }
  vector<int> v;
  for (int i = 0; i < n; i++) {
    if (!vis[i]) {
      dfs(i);
      mn = 1e9 + 5;
      dfs1(i, -1, 0);
      v.push_back(mn);
    }
  }
  sort(v.rbegin(), v.rend());
  if (v.size() >= 2) {
    ans = max(ans, v[0] + v[1] + l);
  }
  if (v.size() >= 3) {
    ans = max(ans, v[1] + v[2] + 2 * l);
  }
  return ans;
}

Compilation message (stderr)

dreaming.cpp: In function 'void dfs(int)':
dreaming.cpp:12:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   12 |   for (auto [child, w] : ad[node]) {
      |             ^
dreaming.cpp: In function 'void dfs1(int, int, int)':
dreaming.cpp:26:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   26 |   for (auto [child, w] : ad[node]) {
      |             ^

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