Submission #1182490

#	Time	Username	Problem	Language	Result	Execution time	Memory
1182490		swishy123	Dreaming (IOI13_dreaming)	C++20	100 / 100	67 ms	36624 KiB

dreaming

#include <iostream>
#include <algorithm>
#include <vector>
#include <random>
#include <chrono>
#include <set>
#include <map>
#include <stack>
#include <functional>
#include <iomanip>
#include <queue>
#include <cassert>
#include <complex>
#include <cstring>
#include <memory>
#include <bitset>
#include <sstream>
#include <cmath>
#include <numeric>
#include <numbers>
#include <fstream>
#include "dreaming.h"

using namespace std;

#ifndef template
#ifndef define
 
#define ll long long
#define ld long double
#define pl pair<ll, ll>
#define pi pair<int, int>
#define nl cout << '\n';
#define x first
#define y second 
#define cbit(x) __builtin_popcountll(x)
#define uid(a, b) uniform_int_distribution<ll>(a, b)(rng) 
#define siz(x) (int)x.size()
 
#endif
 
#ifndef print
void print(size_t x) {cout << x << ' ';}
void print(int x) {cout << x << ' ';}
void print(long long x) {cout << x << ' ';}
void print(float x) {cout << x << ' ';}
void print(long double x) {cout << x << ' ';}
void print(char x) {cout << x << ' ';}
void print(const char* x) {cout << x << ' ';}
void print(bool x) {cout << x << ' ';}
void print(string &x) {cout << x << ' ';}
 
template<typename T, typename V>
void print(pair<T, V> &p) {print(p.x); print(p.y);}
template<typename T>
void print(vector<T> v) {for (int i = 0; i < v.size(); i++) print(v[i]);}
template<typename T>
void print(vector<vector<T>> v) {
    for (int i = 0; i < v.size(); i++){
        for (int j = 0; j < v[i].size(); j++)
            print(v[i][j]);
        nl;
    }
}
template <typename T, typename... V>
void print(T t, V&&... v) {print(t); print(v...);}
 
#endif
 
#ifndef read
void read(int &x) {cin >> x;}
void read(long long &x) {cin >> x;}
void read(unsigned &x) {cin >> x;}
void read(unsigned long long &x) {cin >> x;}
void read(float &x) {cin >> x;}
void read(long double &x) {cin >> x;}
void read(char &x) {cin >> x;}
void read(string &x) {cin >> x;}
void read(bool &x) {cin >> x;}
 
template<typename T> 
void read(vector<T> &v) {
    for (int i = 0; i < v.size(); i++)
        read(v[i]);
}
template <typename T, typename... V>
void read(T &t, V&... v) {read(t); read(v...);}
#endif
 
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
template<class T> bool maxi(T& a, const T& b) {
    return a < b ? a = b, 1 : 0;
}
template<class T> bool mini(T& a, const T& b) {
    return a > b ? a = b, 1 : 0;
}
template<class... Args>
auto vec(size_t n, Args&&... args) {
    if constexpr(sizeof...(args) == 1)
        return vector(n, args...);
    else
        return vector(n, vec(args...));
}

#endif

using namespace std;
const ll inf = 1e15;
const ll def = 2e5+1;
const ll mod = 998244353;

int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
    vector<vector<pi>> edg(N);
    for (int i = 0; i < M; i++){
        edg[A[i]].push_back({B[i], T[i]});   
        edg[B[i]].push_back({A[i], T[i]});   
    }
    int max_dis = 0;
    vector<int> dis;

    auto dp = vec(N, (int)-1e9);
    for (int i = 0; i < N; i++){
        if (dp[i] != -1e9)
            continue;  
        auto dfs = [&](int u, int pre, auto&& dfs) -> void{
            dp[u] = 0;
            for (auto [v, w] : edg[u]){
                if (v == pre)
                    continue;
                dfs(v, u, dfs);
                maxi(dp[u], dp[v] + w);
            }
        };
        dfs(i, -1, dfs);
        int ligma = 1e9;

        auto get = [&](int u, int pre, int crr, auto&& get) -> void{
            mini(ligma, max(dp[u], crr));
            maxi(max_dis, dp[u] + crr);
            vector<pi> child;
            for (auto [v, w] : edg[u]){
                if (v == pre)
                    continue;
                child.push_back({v, w});
            }
            int m = child.size();
            auto pref = vec(m + 1, 0);
            auto suff = pref;

            for (int i = 1; i <= m; i++){
                auto [v, w] = child[i - 1];
                pref[i] = max(pref[i - 1], dp[v] + w);
            }
            for (int i = m - 1; i >= 0; i--){
                auto [v, w] = child[i];
                suff[i] = max(suff[i + 1], dp[v] + w);
            }
            for (int i = 0; i < m; i++){
                auto [v, w] = child[i];
                get(v, u, max({pref[i], suff[i + 1], crr}) + w, get);
            }
        };
        get(i, -1, 0, get);
        dis.push_back(ligma);
    }
    sort(dis.begin(), dis.end());
    int res = max_dis;
    if (dis.size() >= 2)
        maxi(res, dis[dis.size() - 1] + dis[dis.size() - 2] + L);
    if (dis.size() >= 3)
        maxi(res, dis[dis.size() - 2] + dis[dis.size() - 3] + 2 * L);
    return res;
}

// void solve(){  
//     int n, m, l;
//     read(n, m, l);

//     int a[m], b[m], c[m];
//     for (int i = 0; i < m; i++)
//         read(a[i], b[i], c[i]);
//     int res = travelTime(n, m, l, a, b, c);
//     print(res);
// }       

// /*

// */

// int32_t main(){
//     ios_base::sync_with_stdio(0);
//     cin.tie(0); cout.tie(0);

//     if (ifstream("input.txt").good()){
//         freopen("input.txt", "r", stdin);
//         freopen("output.txt", "w", stdout);
//     }

//     int t;
//     t = 1;

//     while (t--){
//         solve();
//         nl;
//     }
// }

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