Submission #707899

#	Time	Username	Problem	Language	Result	Execution time	Memory
707899		Cyanmond	Toy Train (IOI17_train)	C++17	0 / 100	2074 ms	1416 KiB

train

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

using namespace std;

std::vector<int> who_wins(std::vector<int> a, std::vector<int> r, std::vector<int> u, std::vector<int> v) {
    const int n = (int)a.size(), m = (int)u.size();
    std::vector<std::vector<int>> graph(n);
    for (int i = 0; i < m; ++i) {
        graph[u[i]].push_back(v[i]);
    }

    auto calcReachability = [&](const int fin) {
        std::vector<int> reachableV(n, -1);
        reachableV[fin] = 1;
        for (int i = 0; i < n; ++i) {
            auto itr = std::find(graph[i].begin(), graph[i].end(), i);
            if (r[i] == 0 and a[i] == 0 and itr != graph[i].end()) {
                reachableV[i] = 0;
            }
        }
        for (int x = 0; x < 2 * n; ++x) {
            for (int i = 0; i < n; ++i) {
                if (reachableV[i] != -1) {
                    continue;
                }
                if (a[i] == 1) {
                    bool isOk = false, isRa = true;
                    for (const int t : graph[i]) {
                        if (reachableV[t] == 1) {
                            isOk = true;
                        }
                        if (reachableV[t] == -1) {
                            isRa = false;
                        }
                    }
                    if (isOk) {
                        reachableV[i] = 1;
                    } else if (isRa) {
                        reachableV[i] = 0;
                    }
                } else {
                    bool isOk = true, isRa = true;
                    for (const int t : graph[i]) {
                        if (reachableV[t] != 1) {
                            isOk = false;
                        }
                        if (reachableV[t] == -1) {
                            isRa = false;
                        }
                    }
                    if (isOk) {
                        reachableV[i] = 1;
                    } else if (isRa) {
                        reachableV[i] = 0;
                    }
                }
            }
        }
        for (auto &e : reachableV) {
            if (e == -1) {
                e = 0;
            }
        }
        reachableV[fin] = -1;
        if (a[fin] == 1) {
            bool isOk = false;
            for (const int t : graph[fin]) {
                if (reachableV[t] == 1) {
                    isOk = true;
                } else if (t == fin) {
                    isOk = true;
                }
            }
            if (isOk) {
                reachableV[fin] = 1;
            } else {
                reachableV[fin] = 0;
            }
        } else {
            bool isOk = true;
            for (const int t : graph[fin]) {
                if (reachableV[t] == 0) {
                    isOk = false;
                }
            }
            if (isOk) {
                reachableV[fin] = 1;
            } else {
                reachableV[fin] = 0;
            }
        }
        return reachableV;
    };
    std::vector<std::vector<int>> reachability(n);
    for (int i = 0; i < n; ++i) {
        reachability[i] = calcReachability(i);
    }

    std::vector<int> answer(n);
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            if (r[j] == 1) {
                if (reachability[j][i] == 1 and reachability[j][j] == 1) {
                    answer[i] = 1;
                }
            }
        }
    }
    return answer;
}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 10
• Subtask 3: 0 / 11
• Subtask 4: 0 / 11
• Subtask 5: 0 / 12
• Subtask 6: 0 / 51