Submission #414941

#	Time	Username	Problem	Language	Result	Execution time	Memory
414941		snasibov05	Dreaming (IOI13_dreaming)	C++14	100 / 100	136 ms	25192 KiB

dreaming

#include "dreaming.h"
#include <vector>
#include <algorithm>

using namespace std;

#define pb push_back
#define pii pair<int, int>
#define oo 1000000000
#define s second
#define f first

vector<vector<pii>> ed;
vector<bool> visited;
vector<int> best;
vector<int> mx;
vector<int> cur;
vector<int> dist;
vector<int> res;

void dfs(int v){
    cur.pb(v);
    visited[v] = true;
    for (auto [x, t] : ed[v]){
        if (!visited[x]) {
            dfs(x);
            dist[v] = max(dist[v], dist[x] + t);
        }
    }
}

void mxdist(int v, int pr, int d){
    res[v] = max(dist[v], d);

    vector<pii> a;
    for (auto [x, t] : ed[v]){
        if (x == pr) a.pb({d, x});
        else a.pb({dist[x] + t, x});
    }

    sort(a.rbegin(), a.rend());

    for (auto [x, t] : ed[v]){
        if (x == pr) continue;
        if (a[0].s != x) mxdist(x, v, a[0].f + t);
        else{
            if (a.size() == 1) mxdist(x, v, t);
            else mxdist(x, v, a[1].f + t);
        }
    }

}

void findmn(int v){

    cur.clear();
    dfs(v);
    int Min = oo, Max = 0;
    mxdist(v, -1, 0);
    for (auto x : cur){
        Min = min(Min, res[x]);
        Max = max(Max, res[x]);
    }

    best.pb(Min);
    mx.pb(Max);

}

int travelTime(int n, int m, int l, int a[], int b[], int t[]) {

    ed.resize(n);
    visited.resize(n);
    dist.resize(n);
    res.resize(n);

    for (int i = 0; i < m; ++i) {
        ed[a[i]].pb({b[i], t[i]});
        ed[b[i]].pb({a[i], t[i]});
    }

    for (int i = 0; i < n; ++i) {
        if (!visited[i]) findmn(i);
    }

    sort(best.rbegin(), best.rend());
    sort(mx.rbegin(), mx.rend());

    if (mx.size() == 1) return mx[0];
    if (mx.size() == 2) return max(best[0] + best[1] + l, mx[0]);

    return max(max(best[0]+best[1]+l, best[1]+best[2]+2*l), mx[0]);

}

Compilation message (stderr)

dreaming.cpp: In function 'void dfs(int)':
dreaming.cpp:24:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   24 |     for (auto [x, t] : ed[v]){
      |               ^
dreaming.cpp: In function 'void mxdist(int, int, int)':
dreaming.cpp:36:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   36 |     for (auto [x, t] : ed[v]){
      |               ^
dreaming.cpp:43:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   43 |     for (auto [x, t] : ed[v]){
      |               ^

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