Submission #795219

#	Time	Username	Problem	Language	Result	Execution time	Memory
795219		fatemetmhr	Roller Coaster Railroad (IOI16_railroad)	C++17	100 / 100	337 ms	51108 KiB

railroad

//  ~ Be Name Khoda ~  //

#include "railroad.h"
#include <bits/stdc++.h>
//#pragma GCC optimize ("O3")
//#pragma GCC target("avx2")
//#pragma GCC optimize("unroll-loops,Ofast")

using namespace std;

typedef long long ll;

#define pb       push_back
#define mp       make_pair
#define all(x)   x.begin(), x.end()
#define fi       first
#define se       second

const int maxn  =  1e6   + 10;
const int maxn5 =  5e5   + 10;
const int maxnt =  1.2e6 + 10;
const int maxn3 =  1e3   + 10;
const int mod   =  1e9   + 7;
const ll  inf   =  1e18;

vector <int> num, adj[maxn5];
int cnt[maxn5], xx = 0, par[maxn5], cmp[maxn5];
bool mark[maxn5];
vector <pair<int, int>> ed;

void dfs(int v){
    mark[v] = true;
    cmp[v] = xx;
    for(auto u : adj[v]) if(!mark[u])
        dfs(u);
}

int get_par(int a){return par[a] == -1 ? a : par[a] = get_par(par[a]);}

long long plan_roller_coaster(std::vector<int> s, std::vector<int> t) {
    int n = s.size();
    for(int i = 0; i < n; i++){
        num.pb(s[i]);
        num.pb(t[i]);
    }
    num.pb(0);
    num.pb(mod);
    sort(all(num));
    num.resize(unique(all(num)) - num.begin());
    for(int i = 0; i < n; i++) if(s[i] != t[i]){
        s[i] = lower_bound(all(num), s[i]) - num.begin();
        t[i] = lower_bound(all(num), t[i]) - num.begin();
        adj[s[i]].pb(t[i]);
        adj[t[i]].pb(s[i]);
        cnt[t[i] + 1]--;
        cnt[s[i] + 1]++;

    }
    adj[0].pb(int(num.size()) - 1);
    adj[int(num.size()) - 1].pb(0);
    cnt[1]--;
    int cur = 0;
    ll ans = 0;
    for(int i = 0; i < num.size(); i++){
        cur += cnt[i];
        if(cur > 0)
            ans += ll(cur) * (num[i] - num[i - 1]);
        //cout << i << ' ' << cur << endl;
        if(i && cur){
            adj[i].pb(i - 1);
            adj[i - 1].pb(i);
        }
    }
    for(int i = 0; i < num.size(); i++) if(!mark[i]){
        dfs(i);
        xx++;
    }
    for(int i = 1; i < num.size(); i++) if(cmp[i] != cmp[i - 1])
        ed.pb({num[i] - num[i - 1], i});
    memset(par, -1, sizeof par);
    sort(all(ed));
    for(auto [val, id] : ed){
        int u = get_par(cmp[id]), v = get_par(cmp[id - 1]);
        if(u == v)
            continue;
        ans += val;
        par[u] = v;
    }
    return ans;
}

Compilation message (stderr)

railroad.cpp: In function 'long long int plan_roller_coaster(std::vector<int>, std::vector<int>)':
railroad.cpp:64:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   64 |     for(int i = 0; i < num.size(); i++){
      |                    ~~^~~~~~~~~~~~
railroad.cpp:74:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   74 |     for(int i = 0; i < num.size(); i++) if(!mark[i]){
      |                    ~~^~~~~~~~~~~~
railroad.cpp:78:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   78 |     for(int i = 1; i < num.size(); i++) if(cmp[i] != cmp[i - 1])
      |                    ~~^~~~~~~~~~~~

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