Submission #1138734

#	Time	Username	Problem	Language	Result	Execution time	Memory
1138734		steveonalex	Roller Coaster Railroad (IOI16_railroad)	C++20	100 / 100	185 ms	19084 KiB

railroad

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
ll lcm(ll a, ll b){return a / gcd(a, b) * b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ull mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
double rngesus_d(double l, double r){
    double cur = rngesus(0, MASK(60) - 1);
    cur /= MASK(60) - 1;
    return l + cur * (r - l);
}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

#include "railroad.h"

struct DSU{
    int n;
    vector<int> parent, sz;

    DSU(int _n){
        n = _n;
        parent.resize(n); sz.resize(n, 1);
        for(int i = 0; i<n; ++i) parent[i] = i;
    }

    int find_set(int u){return (u == parent[u]) ? u : (parent[u] = find_set(parent[u]));}
    bool same_set(int u, int v){return find_set(u) == find_set(v);}

    bool join_set(int u, int v){
        u = find_set(u), v = find_set(v);
        if (u != v){
            if (sz[u] < sz[v]) swap(u, v);
            parent[v] = u;
            sz[u] += sz[v];
            return true;
        }
        return false;
    }

    int get_size(int u){return sz[find_set(u)];}
};

const int INF = 1e9 + 69;

ll plan_roller_coaster(vector<int> s, vector<int> t) {
    vector<pair<int, int>> road;
    for(int i = 0; i < (int) s.size(); ++i) road.push_back({s[i], t[i]});
    road.push_back({INF, -INF});

    vector<int> X;
    for(pair<int, int> i: road){
        X.push_back(i.first);
        X.push_back(i.second);
    }

    remove_dup(X);

    int m = X.size();
    vector<int> sum(m);
    DSU mst(m);
    for(auto &i: road){
        i.first = lower_bound(ALL(X), i.first) - X.begin();
        i.second = lower_bound(ALL(X), i.second) - X.begin();
        sum[i.first]--;
        sum[i.second]++;
        mst.join_set(i.first, i.second);
    }

    for(int i = 1; i < m; ++i) sum[i] += sum[i-1];


    ll ans = 0;
    for(int i = 0; i + 1 < m; ++i){
        if (sum[i] < 0) {
            int diff = -sum[i];
            sum[i] += diff;
            ans += 1LL * diff * (X[i+1] - X[i]);
            mst.join_set(i, i + 1);
        }
    }

    for(int i = 1; i < m; ++i){
        if (sum[i-1] > 0) mst.join_set(i-1, i); 
    }

    vector<array<int, 3>> edges;
    for(int i = 1; i < m; ++i) edges.push_back({{X[i] - X[i-1], i - 1, i}});

    sort(ALL(edges));

    for(auto i: edges) if (mst.join_set(i[1], i[2])) ans += i[0];

    return ans;
}


// int main(void){
//     ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
//     clock_t start = clock();

//     int n; cin >> n;
//     vector<int> s(n), t(n);
//     for(int i = 0; i < n; ++i) cin >> s[i];
//     for(int i = 0; i < n; ++i) cin >> t[i];

//     cout << plan_roller_coaster(s, t) << "\n";

//     cerr << "Time elapsed: " << clock() - start << " ms\n";
//     return 0;
// }

Compilation message (stderr)

railroad.h:1:9: warning: #pragma once in main file
    1 | #pragma once
      |         ^~~~
railroad_c.h:1:9: warning: #pragma once in main file
    1 | #pragma once
      |         ^~~~

• Subtask 1: 11 / 11
• Subtask 2: 23 / 23
• Subtask 3: 30 / 30
• Subtask 4: 36 / 36