Submission #1204919

#	Time	Username	Problem	Language	Result	Execution time	Memory
1204919		HasanV11010238	Ancient Books (IOI17_books)	C++20	50 / 100	134 ms	19784 KiB

books

#include "books.h"
#include <bits/stdc++.h>
#define ll long long
using namespace std;
vector<int> vis, to, mm;
int ri;
void dfs(int x){
	ri = max(ri, x);
	vis[x] = 1;
	if (vis[to[x]] == 0) dfs(to[x]);
}
void ass(int x, int va){
	mm[x] = va;
	vis[x] = 2;
	if (vis[to[x]] == 1) ass(to[x], va);
}

long long minimum_walk(std::vector<int> p, int s) {
	int n = p.size();
	ll ans = 0;
	for (int i = 0; i < n; i++){
		ans += abs(i - p[i]);
	}
	to = p;
	vis.assign(n, 0), mm.assign(n, 0);
	for (int i = 0; i < n; i++){
		if (vis[i] == 0){
			ri = 0;
			dfs(i);
			ass(i, ri);
		}
	}
	int tt = 0, wh = n - 1;
	while (to[wh] == wh) wh--;
	for (int i = 0; i < wh; i++){
		if (tt < i) ans += 2;
		tt = max(tt, mm[i]);
	}
	return ans;
}

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