Submission #1208338

#	Time	Username	Problem	Language	Result	Execution time	Memory
1208338		jasonic	Ancient Books (IOI17_books)	C++20	50 / 100	86 ms	8264 KiB

books

#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define fastIO cin.tie(0); ios::sync_with_stdio(false)
#define cerr if(0) cout
#define cerr2 if(0) cout

int n;

ll minimum_walk(vector<int> p, int s) {
    n = size(p);
    vector<bool> vis(n, false);
    ll cntGroups = -1;
    ll ans = 0;
    ll cntNotNeeded = 0;

    for(ll l = 0, i = 0, r = 0, size = 0, total = 0; r < n; i++) {
        
        if(p[i] != i && !vis[i]) {
            ll prev = i;
            ll curr = p[i];
            while(curr != i) {
                cerr << prev << ' ' << curr << ' ' << abs(prev - curr) << '\n';
                vis[prev] = true;
                vis[curr] = true;
                total += abs(prev - curr);
                r = max(r, curr);
                
                prev = p[prev];
                curr = p[curr];
            }
            cerr << prev << ' ' << curr << ' ' << abs(prev - curr) << '\n';
            size += abs(prev - curr);
            cerr << total << '\n';
            total += size;
            size = 0;
        }

        vis[i] = true;
        
        if(i == r) {
            cerr2 << l << ' ' << r << '\n';
            cerr2 << total << '\n';
            
            if(l != r) {
                ans += total;
                cntNotNeeded = 0;
            } else {
                cntNotNeeded++;
            }
            
            cntGroups++;
            l = i+1;
            r = i+1;
            total = 0;
        }
    }
    cerr2 << ans << ' ' << cntGroups << '\n';
    return ans + max(0ll, cntGroups + cntGroups - cntNotNeeded - cntNotNeeded);
}

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