Submission #617719

#	Time	Username	Problem	Language	Result	Execution time	Memory
617719		AbdelmagedNour	Ancient Books (IOI17_books)	C++17	50 / 100	271 ms	31724 KiB

books

#include<bits/stdc++.h>
using namespace std;
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>st1;
tree<int,null_type,greater<int>,rb_tree_tag,tree_order_statistics_node_update>st2;
#include "books.h"
struct BIT{
    vector<long long>Tree;
    int n;
    void init(int N){
        n=N;
        Tree.assign(n+3,0);
    }
    void update(int i,int val){
        i++;
        for(;i<=n;i+=i&-i)Tree[i]+=val;
    }
    long long get(int i){
        long long res=0;
        for(;i;i-=i&-i)res+=Tree[i];
        return res;
    }
    long long gte(int i){
        i++;
        return get(n)-get(i);
    }
    long long lte(int i){
        i++;
        return get(i);
    }
}Tree;
long long minimum_walk(vector<int> p, int s) {
    int n=p.size();
    Tree.init(n+5);
    vector<int>seg1(n),seg2(n+1),mx1(n+1),mx2(n+1);
    long long res=0;
    for(int i=0;i<n;i++){
        Tree.update(p[i],1);
        seg1[i]=Tree.gte(i);
    }
    for(int i=0;i<n;i++){
        Tree.update(p[i],-1);
        seg2[i]=Tree.lte(i);
    }
    for(int i=n-1;i>=0;i--)mx1[i]=max(mx1[i+1],seg1[i]);
    for(int i=0;i<n;i++)mx2[i]=max((i?mx2[i-1]:0),seg1[i]);
    for(int i=0;i<n;i++){
        if(seg1[i]==0&&seg2[i]==0){
            if(i>=s&&mx1[i])res+=2;
            else if(i<s&&mx2[i])res+=2;
        }
        else res+=seg1[i]+seg2[i];
    }
    return res;
}

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