Submission #296738

#	Time	Username	Problem	Language	Result	Execution time	Memory
296738		dandrozavr	Ancient Books (IOI17_books)	C++14	0 / 100	1 ms	544 KiB

books

#include "books.h"
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define ll long long
#define ld long double
#define fi first
#define se second
#define F first
#define S second
#define pii pair < int , int >
#define _ <<" "<<
#define TIME 1.0 * clock() / CLOCKS_PER_SEC

vector < int > a;
int S, n;

map < vector < int > , int > mp[30];
int brute(vector < int > p, int s){
    if (mp[s].count(p)) return mp[s][p];
    mp[s][p] = 1e7;
    bool bad = 0;
    for (int i = 0; i < n; ++i)
        if (p[i] != i){
            bad = 1;
            break;
        }
    if (!bad){
        mp[s][p] = abs(s - S);
        return abs(s - S);
    }
    int pos = -1;
    bool byl[n] = {};
    for (int i = 0; i < n; ++i)
        if (p[i] != n)
            byl[p[i]] = 1;
    for (int i = 0; i < n; ++i)
        if (!byl[i]){
            pos = i;
            break;
        }
    int ans = 1e7;
    for (int i = 0; i < n; ++i){
        int dist = abs(i - s);
        ans = min(ans, dist + brute(p, i));
    }
    if (pos == -1){
        int temp = p[s];
        p[s] = 0;
        ans = min(ans, brute(p, s));
        p[s] = temp;
    }

    if (pos != -1){
        for (int i = 0; i < n; ++i)
            if (p[i] != n){
                int dist = abs(s - i);
                int temp = p[i];
                p[i] = pos;
                ans = min(ans, dist + brute(p, i));
                p[i] = temp;
            } else {
                p[i] = pos;
                int dist = abs(i - s);
                ans = min(ans, dist + brute(p, i));
                p[i] = n;
            }
    }
//    for (int i : p) cout << i << " "; cout << endl;
//    if (p[0] == 0 && p[1] == 2 && p[2] == 3 && p[3] == 1){
//        for (int i : p) cout << i << " ";
//        cout << endl;
//        cout << s _ ans _ pos << endl << endl;
//    }
    mp[s][p] = ans;
    return ans;
}

long long minimum_walk(std::vector<int> p, int s) {
    S = s;
    a = p;
    n = p.size();
    if (n <= 4)
        return brute(p, s);
}

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:85:1: warning: control reaches end of non-void function [-Wreturn-type]
   85 | }
      | ^

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