Submission #892992

#	Time	Username	Problem	Language	Result	Execution time	Memory
892992		abcvuitunggio	Ancient Books (IOI17_books)	C++17	100 / 100	112 ms	30744 KiB

books

#include "books.h"
#include <bits/stdc++.h>
using namespace std;
int vis[1000001],r[1000001],g[1000001],nxt[1000001];
vector <pair <int, pair <int, int>>> e;
long long minimum_walk(vector <int> p, int s){
    int n=p.size(),lo=n,hi=0;
    iota(nxt,nxt+n,0);
    vector <pair <int, int>> tmp;
    long long d=0;
    for (int i=0;i<n;i++)
        if (!vis[i]){
            int x=i;
            while (!vis[x]){
                vis[x]=1;
                g[x]=i;
                r[i]=max(r[i],x);
                d+=abs(x-p[x]);
                x=p[x];
            }
          	if (r[i]!=i||i==s){
                lo=min(lo,i);
                hi=max(hi,r[i]);
          	}
        }
    int L=g[s],R=r[g[s]];
    while (L>lo||R<hi){
        if (nxt[L]!=R){
            int j=nxt[L]+1;
            nxt[L]=nxt[j];
            L=min(L,g[j]);
            R=max(R,r[g[j]]);
            continue;
        }
        int tmpl=L,tmpr=R,ch=0;
        long long d2=d;
        while (L>lo||R<hi){
            d+=2;
            d2+=((L>lo)+(R<hi))*2;
            L=max(L-1,lo);
            R=min(R+1,hi);
            int newL=g[L],newR=r[g[R]];
            while (L>=newL){
                if (r[g[L]]>tmpr){
                    R=r[g[L]];
                    L=g[L];
                    ch=1;
                    break;
                }
                newL=min(newL,g[L]);
                L--;
            }
            if (ch)
                break;
            L++;
            while (R<=newR){
                if (g[R]<tmpl){
                    L=g[R];
                    R=r[g[R]];
                    ch=1;
                    break;
                }
                newR=max(newR,r[g[R]]);
                R++;
            }
            if (ch)
                break;
            R--;
        }
        if (!ch)
            d=d2;
    }
    return d;
}

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