Submission #423261

#	Time	Username	Problem	Language	Result	Execution time	Memory
423261		MDario	Ancient Books (IOI17_books)	C++11	50 / 100	179 ms	26832 KiB

books

#include "books.h"
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define F first.first
#define S first.second
#define T second
long long minimum_walk(vector<int> p, int s){
    ll n=p.size(), r=0, x=n, y=0, z=-1;
    bool b[n];
    for(int i=0; i<n; i++){
        b[i]=0;
        if(i==p[i])b[i]=1;
    }
    vector<pair<pair<ll, ll>, vector<ll>>> v;
    vector<ll> v1;
    for(ll i=0; i<n; i++){
        if(!b[i]){
            v1.clear();
            //cout << z << " ";
            if(i>=z){
                if(z!=-1)r+=2*(i-z);
            }
            r+=p[i]-i;
            y=p[i];
            while(y!=i){
                v1.push_back(y);
                z=max(z, y);
                b[y]=1;
                r+=abs(p[y]-y);
                y=p[y];
            }
            v1.push_back(y);
            b[y]=1;
            z=max(z, y);
            v.push_back({{i, z}, v1});
        }
    }
    if(v.empty())return 0;
    unique(v.begin(), v.end());
    sort(v.begin(), v.end());
    if(s>v.back().S)return r+2*(s-v.back().S);
    if(s<=v[0].F) return r+2*(v[0].F-s);
    x=n;
    z=0;
    for(int i=0; i<v.size(); i++){
//        if(i+1==v.size()){
                //cout << v[i].F << " " << v[i].S << "\n";
            if(s>=v[i].F&&s<=v[i].S&&v[i].S>z){
                for(int t=0; t<v[i].T.size(); t++)x=min(x, abs(s-v[i].T[t]));
                z=v[i].S;
            }
//        }
//        else if(v[i+1].F!=v[i].F){
//            if(s>=v[i].F&&s<=v[i].S&&v[i].S>z){
//                for(int t=0; t<v[i].T.size(); t++)x=min(x, abs(s-v[i].T[t]));
//                z=v[i].S;
//            }
//        }
    }
    if(x==n)return r;
	return r+2*x;
}

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:46:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<std::pair<long long int, long long int>, std::vector<long long int> > >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |     for(int i=0; i<v.size(); i++){
      |                  ~^~~~~~~~~
books.cpp:50:31: 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 t=0; t<v[i].T.size(); t++)x=min(x, abs(s-v[i].T[t]));
      |                              ~^~~~~~~~~~~~~~

• Subtask 1: 12 / 12
• Subtask 2: 10 / 10
• Subtask 3: 28 / 28
• Subtask 4: 0 / 20
• Subtask 5: 0 / 30