Submission #971979

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
971979	2024-04-29T16:09:12 Z	thinknoexit	Longest Trip (IOI23_longesttrip)	C++17	Compilation error	0 ms	0 KB

longesttrip

#include <bits/stdc++.h>
#include "longesttrip.h"
using namespace std;
using ll = long long;
int n;
vector<int> longest_trip(int N, int D) {
    n = N;
    vector<int> p1, p2;
    p1.push_back(0);
    for (int i = 1;i < n;i++) {
        if (p2.empty()) {
            if (are_connected({ p1.back() }, { i })) p1.push_back(i);
            else p2.push_back(i);
        }
        else {
            if (are_connected({ p1.back() }, { p2.back(), i })) {
                p1.push_back(i);
                if (are_connected({ p1.back() }, { p2.back() })) {
                    reverse(p2.begin(), p2.end());
                    for (auto& x : p2) p1.push_back(x);
                    p2.clear();
                }
            }
            else {
                p2.push_back(i);
            }
        }
    }
    if (p1.size() > p2.size()) swap(p1, p2);
    if ((int)p2.size() == n) return p2;
    int l = 0, r = p1.size();
    while (l < r) {
        int mid = (l + r) / 2;
        vector<int> t;
        for (int j = 0;j <= mid;j++) t.push_back(p1[j]);
        if (are_connected(t, p2)) r = mid;
        else l = mid + 1;
    }
    if (r == (int)p1.size()) return p2;
    {
        bool chl = l == 0;
        bool chr = are_connected({ p1.back() }, p2);
        if (!chl) {
            if (chr) l = p1.size() - 1;
            vector<int> p3;
            int idx = l;
            for (int i = 0;i < (int)p1.size();i++) {
                p3.push_back(p1[(i + l) % ((int)p1.size())]);
            }
            swap(p1, p3);
        }
    }
    if (are_connected(p1.front(), p2.back())) {
        vector<int> ans;
        for (auto& x : p2) ans.push_back(x);
        for (auto& x : p1) ans.push_back(x);
        return ans;
    }
    l = 0, r = p2.size() - 2;
    while (l < r) {
        int mid = (l + r) / 2;
        vector<int> t;
        for (int j = 0;j <= mid;j++) t.push_back(p2[j]);
        if (are_connected(t, p1.front())) r = mid;
        else l = mid + 1;
    }
    {
        bool chl = l == 0;
        bool chr = are_connected({ p2[l] }, { p1.front() });
        if (!chl) {
            if (chr) l = p2.size() - 1;
            vector<int> p3;
            int idx = l;
            for (int i = 0;i < (int)p1.size();i++) {
                p3.push_back(p1[(i + l) % ((int)p1.size())]);
            }
            swap(p2, p3);
        }
    }
    reverse(p2.begin(), p2.end());
    vector<int> ans;
    for (auto& x : p2) ans.push_back(x);
    for (auto& x : p1) ans.push_back(x);
    return ans;
}

Compilation message

longesttrip.cpp: In function 'std::vector<int> longest_trip(int, int)':
longesttrip.cpp:46:17: warning: unused variable 'idx' [-Wunused-variable]
   46 |             int idx = l;
      |                 ^~~
longesttrip.cpp:53:31: error: could not convert 'p1.std::vector<int>::front()' from '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} to 'std::vector<int>'
   53 |     if (are_connected(p1.front(), p2.back())) {
      |                       ~~~~~~~~^~
      |                               |
      |                               __gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type {aka int}
longesttrip.cpp:64:38: error: could not convert 'p1.std::vector<int>::front()' from '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} to 'std::vector<int>'
   64 |         if (are_connected(t, p1.front())) r = mid;
      |                              ~~~~~~~~^~
      |                                      |
      |                                      __gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type {aka int}
longesttrip.cpp:73:17: warning: unused variable 'idx' [-Wunused-variable]
   73 |             int idx = l;
      |                 ^~~