Submission #983991

#	Time	Username	Problem	Language	Result	Execution time	Memory
983991		CSQ31	Ancient Books (IOI17_books)	C++17	50 / 100	109 ms	34932 KiB

books

#include "books.h"
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define sz(a) (int)(a.size())
#define all(a) a.begin(),a.end()
typedef long long int ll;
typedef pair<int,int> pii;
const int MAXN = 1e6+1;
int par[MAXN];
int mn[MAXN],mx[MAXN];

int find(int x){
	if(x==par[x])return x;
	return par[x] = find(par[x]);
}

void unite(int a,int b){
	a = find(a);
	b = find(b);
	if(a==b)return;
	mx[b] = max(mx[b],mx[a]);
	mn[b] = min(mn[b],mn[a]);
	par[a] = b;
}

ll minimum_walk(vector<int> p, int s) {
	int n = sz(p);
	ll ans = 0;
	for(int i=0;i<n;i++)ans+=abs(i-p[i]);
	for(int i=0;i<n;i++){
		par[i] = i;
		mn[i] = min(i,p[i]);
		mx[i] = max(i,p[i]);
	}

	for(int i=0;i<n;i++){
		int l = min(i,p[i]);
		int r = max(i,p[i]);
		if(l==r)continue;

		while(true){
			l = find(l);
			if(l >= r)break;
			unite(l,l+1);
			l = find(l);
		}
	}
	int cur = 0;
	while(true){
		int nxt = cur;
		while(nxt < n){
			if(find(nxt) > nxt)break;
			nxt++;
		}
		if(nxt == n)break;
		ans += 2*(nxt - cur);
		cur = find(nxt);
	}
	return ans;	
}

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