Submission #570291

#	Time	Username	Problem	Language	Result	Execution time	Memory
570291		cheissmart	Dreaming (IOI13_dreaming)	C++14	100 / 100	129 ms	26216 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>
#define IO_OP std::ios::sync_with_stdio(0); std::cin.tie(0);
#define F first
#define S second
#define V vector
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define SZ(v) int((v).size())
#define ALL(v) (v).begin(), (v).end()

using namespace std;

typedef long long ll;
typedef pair<int, int> pi;
typedef V<int> vi;

string _reset = "\u001b[0m", _yellow = "\u001b[33m", _bold = "\u001b[1m";
void DBG() { cerr << "]" << _reset << endl; }
template<class H, class...T> void DBG(H h, T ...t) {
    cerr << to_string(h);
    if(sizeof ...(t)) cerr << ", ";
    DBG(t...);
}
#ifdef CHEISSMART
#define debug(...) cerr << _yellow << _bold << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define debug(...)
#endif

const int INF = 1e9 + 7, N = 1e5 + 7;

V<pi> G[N];
bool vis[N];
int down[N];

void dfs1(int u, int& mx, int p = -1) {
    vis[u] = true;
    vi aux({0});
    for(auto[v, w]:G[u]) if(v != p) {
        dfs1(v, mx, u);
        down[u] = max(down[u], down[v] + w);
        aux.PB(down[v] + w);
    }
    sort(ALL(aux), greater<>());
    if(SZ(aux) > 1) mx = max(mx, aux[0] + aux[1]);
}

void dfs2(int u, int up, int& mn, int p = -1) {
    mn = min(mn, max(up, down[u]));
    vi aux({up});
    for(auto[v, w]:G[u]) if(v != p)
        aux.PB(down[v] + w);
    sort(ALL(aux), greater<>());
    for(auto[v, w]:G[u]) if(v != p) {
        int new_up = aux[aux[0] == down[v] + w] + w;
        dfs2(v, new_up, mn, u);
    }
}

int travelTime(int n, int m, int l, int a[], int b[], int t[]) {
    assert(m <= n - 1);
    for(int i = 0; i < m; i++) {
        G[a[i]].EB(b[i], t[i]);
        G[b[i]].EB(a[i], t[i]);
    }
    int ans = 0;
    vi aux;
    for(int i = 0; i < n; i++) if(!vis[i]) {
        int mx = 0;
        dfs1(i, mx);
        ans = max(ans, mx);

        int mn = INF;
        dfs2(i, 0, mn);
        aux.PB(mn);
    }
    sort(ALL(aux), greater<>());
    if(SZ(aux) > 1) ans = max(ans, aux[0] + aux[1] + l);
    if(SZ(aux) > 2) ans = max(ans, aux[1] + aux[2] + l * 2);
    return ans;
}

Compilation message (stderr)

dreaming.cpp: In function 'void dfs1(int, int&, int)':
dreaming.cpp:41:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   41 |     for(auto[v, w]:G[u]) if(v != p) {
      |             ^
dreaming.cpp: In function 'void dfs2(int, int, int&, int)':
dreaming.cpp:53:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   53 |     for(auto[v, w]:G[u]) if(v != p)
      |             ^
dreaming.cpp:56:13: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   56 |     for(auto[v, w]:G[u]) if(v != p) {
      |             ^

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