Submission #371098

#	Time	Username	Problem	Language	Result	Execution time	Memory
371098		doowey	Ancient Books (IOI17_books)	C++14	22 / 100	2082 ms	24556 KiB

books

#include <bits/stdc++.h>
#include "books.h"

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;

#define fi first
#define se second
#define mp make_pair

int n;
const int N = 1010;
int lef[N], rig[N];
bool vis[N];
bool has[N];

int tl, tr;

int ash[1005][1005];


void extend(int &li, int &ri){
    int ni = min(lef[li],lef[ri]);
    int nj = max(rig[li],rig[ri]);
    while(li > ni || ri < nj){
        if(li > ni){
            li--;
            ni = min(ni, lef[li]);
            nj = max(nj, rig[li]);
        }
        else{
            ri++;
            ni = min(ni, lef[ri]);
            nj = max(nj, rig[ri]);
        }
    }
}

int solve(int li, int ri){
    if(li < tl || ri > tr) return (int)1e9 + 9;
    if(ash[li][ri] != -1) return ash[li][ri];
    extend(li, ri);
    if(li == tl && ri == tr) return ash[li][ri]=0;
    return ash[li][ri]=min(solve(li-1,ri), solve(li,ri+1)) + 2;
}

long long minimum_walk(vector<int> p, int s) {
	n = p.size();
	int id;
	int low, high;
	ll sol = 0;
    tl = tr = s;
    for(int i = 0 ; i < n; i ++ ){
        for(int j = 0 ; j < n; j ++ ){
            ash[i][j]=-1;
        }
    }
	for(int i = 0 ; i < n; i ++ ){
        sol += abs(p[i] - i);
        if(!vis[i]){
            vector<int> cyc;
            id = i;
            while(!vis[id]){
                vis[id]=true;
                cyc.push_back(id);
                id=p[id];
            }
            low = n-1;
            high = 0;
            for(auto x : cyc){
                low = min(low, x);
                high = max(high, x);
            }
            for(auto x : cyc){
                lef[x] = low;
                rig[x] = high;
            }
        }
        if(p[i] != i){
            tl = min(tl, i);
            tr = max(tr, i);
        }
	}

	return sol + solve(s, s);
}

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