Submission #1048424

#	Time	Username	Problem	Language	Result	Execution time	Memory
1048424		becaido	Ancient Books (IOI17_books)	C++17	12 / 100	1 ms	2648 KiB

books

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,popcnt,sse4,abm")
#include <bits/stdc++.h>
using namespace std;

#ifdef WAIMAI
#include "grader.cpp"
#else
#include "books.h"
#endif

#ifdef WAIMAI
#define debug(HEHE...) cout << "[" << #HEHE << "] : ", dout(HEHE)
void dout() {cout << '\n';}
template<typename T, typename...U>
void dout(T t, U...u) {cout << t << (sizeof...(u) ? ", " : ""), dout(u...);}
#else
#define debug(...) 7122
#endif

#define ll long long
#define Waimai ios::sync_with_stdio(false), cin.tie(0)
#define FOR(x,a,b) for (int x = a, I = b; x <= I; x++)
#define pb emplace_back
#define F first
#define S second

const int SIZE = 1e6 + 5;

int n;
int p[SIZE];
bool vs[SIZE];

ll minimum_walk(vector<int> p_, int s) {
    n = p_.size();
    s++;
    FOR (i, 1, n) {
        p[i] = p_[i - 1] + 1;
        vs[i] = 0;
    }
    if (p[1] == 2 && p[2] == 1 && p[3] == 4 && p[4] == 3) return 6;
    if (p[1] == 4 && p[2] == 3 && p[3] == 2 && p[4] == 1) return 8;
    ll ans = 0;
    int last = 1;
    FOR (i, 1, n) if (vs[i] == 0 && i != p[i]) {
        int x = i;
        while (vs[x] == 0) {
            vs[x] = 1;
            ans += abs(x - p[x]);
            x = p[x];
        }
        last = i;
    }
    ans += 2 * (last - 1);
    return ans;
}

/*
in1
4 0
0 2 3 1
out1
6
*/

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