Submission #911022

#	Time	Username	Problem	Language	Result	Execution time	Memory
911022		marvinthang	Longest Trip (IOI23_longesttrip)	C++17	85 / 100	11 ms	860 KiB

longesttrip

/*************************************
*    author: marvinthang             *
*    created: 18.01.2024 16:42:53    *
*************************************/

#include "longesttrip.h"
#include <bits/stdc++.h>

using namespace std;

#define                  fi  first
#define                  se  second
#define                left  ___left
#define               right  ___right
#define                TIME  (1.0 * clock() / CLOCKS_PER_SEC)
#define             MASK(i)  (1LL << (i))
#define           BIT(x, i)  ((x) >> (i) & 1)
#define  __builtin_popcount  __builtin_popcountll
#define              ALL(v)  (v).begin(), (v).end()
#define           REP(i, n)  for (int i = 0, _n = (n); i < _n; ++i)
#define          REPD(i, n)  for (int i = (n); i-- > 0; )
#define        FOR(i, a, b)  for (int i = (a), _b = (b); i < _b; ++i) 
#define       FORD(i, b, a)  for (int i = (b), _a = (a); --i >= _a; ) 
#define       FORE(i, a, b)  for (int i = (a), _b = (b); i <= _b; ++i) 
#define      FORDE(i, b, a)  for (int i = (b), _a = (a); i >= _a; --i) 
#define        scan_op(...)  istream & operator >> (istream &in, __VA_ARGS__ &u)
#define       print_op(...)  ostream & operator << (ostream &out, const __VA_ARGS__ &u)
#ifdef LOCAL
    #include "debug.h"
#else
    #define file(name) if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
    #define DB(...) 23
    #define db(...) 23
    #define debug(...) 23
#endif

template <class U, class V> scan_op(pair <U, V>)  { return in >> u.first >> u.second; }
template <class T> scan_op(vector <T>)  { for (size_t i = 0; i < u.size(); ++i) in >> u[i]; return in; }
template <class U, class V> print_op(pair <U, V>)  { return out << '(' << u.first << ", " << u.second << ')'; }
template <size_t i, class T> ostream & print_tuple_utils(ostream &out, const T &tup) { if constexpr(i == tuple_size<T>::value) return out << ")";  else return print_tuple_utils<i + 1, T>(out << (i ? ", " : "(") << get<i>(tup), tup); }
template <class ...U> print_op(tuple<U...>) { return print_tuple_utils<0, tuple<U...>>(out, u); }
template <class Con, class = decltype(begin(declval<Con>()))> typename enable_if <!is_same<Con, string>::value, ostream&>::type operator << (ostream &out, const Con &con) { out << '{'; for (__typeof(con.begin()) it = con.begin(); it != con.end(); ++it) out << (it == con.begin() ? "" : ", ") << *it; return out << '}'; }
vector<int> longest_trip(int N, int D) {
    auto connected_landmark = [&] (int u, int v) {
        return are_connected(vector{u}, vector{v});
    };
    vector <int> path;
    if (D == 3) {
        path.resize(N);
        iota(ALL(path), 0);
    } else if (D == 2) {
        if (!connected_landmark(0, 1)) path = vector{0, 2, 1};
        else if (!connected_landmark(0, 2)) path = vector{0, 1, 2};
        else path = vector{1, 0, 2};
        FOR(i, 3, N) {
            if (!connected_landmark(i, path.back())) path.insert(path.begin(), i);
            else path.push_back(i);
        }
    } else {
        vector <int> left{0}, right{1};
        FOR(i, 2, N) {
            if (connected_landmark(left.back(), i)) left.push_back(i);
            else if (connected_landmark(right.back(), i)) right.push_back(i);
            else {
                left.insert(left.end(), right.rbegin(), right.rend());
                right = vector{i};
            }
        }
        if (left.size() < right.size()) swap(left, right);
        if (right.empty() || !are_connected(left, right)) return left;
        REP(t, 2) {
            if ((int) left.size() > 1) {
                if (connected_landmark(left.back(), right.back())) {
                    left.insert(left.end(), right.rbegin(), right.rend());
                    return left;
                } else if (connected_landmark(left[0], right.back())) {
                    right.insert(right.end(), ALL(left));
                    return right;
                }
                assert(connected_landmark(left[0], left.back()));
            }
            swap(left, right);
        }
        int l = 1, r = (int) left.size() - 1;
        while (l <= r) {
            int m = l + r >> 1;
            if (are_connected(vector(left.begin(), left.begin() + m), right)) r = m - 1;
            else l = m + 1;
        }
        rotate(left.begin(), left.begin() + l, left.end());
        l = 0, r = (int) right.size() - 2;
        while (l <= r) {
            int m = l + r >> 1;
            if (are_connected(vector(right.begin(), right.begin() + m + 1), {left.back()})) r = m - 1;
            else l = m + 1;
        }
        rotate(right.begin(), right.begin() + l, right.end());
        left.insert(left.end(), ALL(right));
        return left;
    }
    return path;
}

Compilation message (stderr)

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:86:23: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   86 |             int m = l + r >> 1;
      |                     ~~^~~
longesttrip.cpp:93:23: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   93 |             int m = l + r >> 1;
      |                     ~~^~~

• Subtask 0: 0 / 0
• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 25 / 25
• Subtask 4: 45 / 60