Submission #591588

#	Time	Username	Problem	Language	Result	Execution time	Memory
591588		knon0501	Roller Coaster Railroad (IOI16_railroad)	C++14	100 / 100	442 ms	47764 KiB

railroad

#include "railroad.h"
#include <bits/stdc++.h>
using namespace std;
const int MX=4e5+5;

long long deg[MX];
int vis[MX];
vector<int> a[MX];
int p[MX];
int f(int x){
    return x==p[x] ? x:p[x]=f(p[x]);
}
long long plan_roller_coaster(std::vector<int> s, std::vector<int> t) {
    int n = (int) s.size();
    vector<long long> v;
    for(int i=0 ; i<n ; i++){
        v.push_back(s[i]);
        v.push_back(t[i]);
    }
    sort(v.begin(),v.end());

    v.erase(unique(v.begin(),v.end()),v.end());

    for(int i=0 ; i<n ; i++){
        deg[lower_bound(v.begin(),v.end(),s[i])-v.begin()]++;
        deg[lower_bound(v.begin(),v.end(),t[i])-v.begin()]--;
        a[lower_bound(v.begin(), v.end(), s[i]) - v.begin()].push_back(lower_bound(v.begin(), v.end(), t[i]) - v.begin());
    }
    if(v.size()==1)return 0;

    long long ans=0;
    if(deg[0]>1){
        a[1].push_back(0);
        ans+=(v[1]-v[0])*(deg[0]-1);
    }
    if(deg[0]<=0)a[0].push_back(1);
    deg[1]+=deg[0]-1;
    for(int i=1 ; i<(int)v.size()-1 ; i++){
        if(deg[i]<0){
            a[i].push_back(i+1);
        }
        if(deg[i]>0){
            a[i+1].push_back(i);
            ans+=deg[i]*(v[i+1]-v[i]);
        }
        deg[i+1]+=deg[i];
    }

    
    for(int i=0 ; i<v.size() ; i++){
        p[i]=i;
    }
    for(int i=0 ; i<v.size() ; i++){
        for(auto x: a[i]){
            p[f(x)]=f(i);
        }
    }
    vector<pair<long long,int>> b;
    for(int i=0 ; i<v.size()-1 ; i++){
        b.push_back({v[i+1]-v[i],i});
    }
    sort(b.begin(),b.end());
    
    for(auto x: b){
        int i=x.second;
        if(f(i)!=f(i+1)){
            p[f(i)]=f(i+1);
            ans+=v[i+1]-v[i];
        }
    }
    return ans;
}

Compilation message (stderr)

railroad.cpp: In function 'long long int plan_roller_coaster(std::vector<int>, std::vector<int>)':
railroad.cpp:50:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   50 |     for(int i=0 ; i<v.size() ; i++){
      |                   ~^~~~~~~~~
railroad.cpp:53:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   53 |     for(int i=0 ; i<v.size() ; i++){
      |                   ~^~~~~~~~~
railroad.cpp:59:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |     for(int i=0 ; i<v.size()-1 ; i++){
      |                   ~^~~~~~~~~~~

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