Submission #1059583

#	Time	Username	Problem	Language	Result	Execution time	Memory
1059583		shiomusubi496	Thousands Islands (IOI22_islands)	C++17	22.75 / 100	1066 ms	263084 KiB

islands

#include "islands.h"

#include <bits/stdc++.h>

#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
#define rep2(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define rrep(i, n) for (int i = (int)(n) - 1; i >= 0; --i)
#define rrep2(i, a, b) for (int i = (int)(b) - 1; i >= (int)(a); --i)

#define all(v) begin(v), end(v)
#define rall(v) rbegin(v), rend(v)

using namespace std;

using ll = long long;

template<class T, class U> bool chmin(T& a, const U& b) { return a > b ? a = b, true : false; }
template<class T, class U> bool chmax(T& a, const U& b) { return a < b ? a = b, true : false; }

struct edge {
    int to, idx;
};

using Graph = vector<vector<edge>>;

std::variant<bool, std::vector<int>> find_journey(int N, int M, std::vector<int> U, std::vector<int> V) {
    Graph G(N);
    rep (i, M) {
        G[U[i]].push_back({V[i], i});
    }
    vector<int> memo;
    int cur = 0;
    while (1) {
        vector<edge> nxts;
        for (auto e : G[cur]) {
            if (memo.empty() || e.idx / 2 != memo.back() / 2) nxts.push_back(e);
        }
        if (nxts.size() == 0) return false;
        if (nxts.size() >= 2) {
            vector<int> ans;
            rep (i, memo.size()) ans.push_back(memo[i]);
            ans.push_back(nxts[0].idx);
            ans.push_back(nxts[0].idx ^ 1);
            ans.push_back(nxts[1].idx);
            ans.push_back(nxts[1].idx ^ 1);
            ans.push_back(nxts[0].idx ^ 1);
            ans.push_back(nxts[0].idx);
            ans.push_back(nxts[1].idx ^ 1);
            ans.push_back(nxts[1].idx);
            rrep (i, memo.size()) ans.push_back(memo[i]);
            return ans;
        }
        memo.push_back(nxts[0].idx);
        cur = nxts[0].to;
    }
    return false;
}

• Subtask 1: 0 / 5
• Subtask 2: 1.75 / 5
• Subtask 3: 21 / 21
• Subtask 4: 0 / 24
• Subtask 5: 0 / 45