Submission #707894

#	Time	Username	Problem	Language	Result	Execution time	Memory
707894		Cyanmond	Toy Train (IOI17_train)	C++17	12 / 100	765 ms	2100 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]);
    }
    // subtask 4
    int chargingS = -1;
    for (int i = 0; i < n; ++i) {
        if (r[i] == 1) {
            if (chargingS == -1) {
                chargingS = i;
            } else {
                assert(false);
            }
        }
    }

    std::vector<int> reachableV(n, -1);
    reachableV[chargingS] = 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[chargingS] = -1;
    if (a[chargingS] == 1) {
        bool isOk = false;
        for (const int t : graph[chargingS]) {
            if (reachableV[t] == 1) {
                isOk = true;
            } else if (t == chargingS) {
                isOk = true;
            }
        }
        if (isOk) {
            reachableV[chargingS] = 1;
        } else {
            reachableV[chargingS] = 0;
        }
    } else {
        bool isOk = true;
        for (const int t : graph[chargingS]) {
            if (reachableV[t] == 0) {
                isOk = false;
            }
        }
        if (isOk) {
            reachableV[chargingS] = 1;
        } else {
            reachableV[chargingS] = 0;
        }
    }

    std::vector<int> answer(n);
    for (int i = 0; i < n; ++i) {
        answer[i] = (reachableV[i] == 1 and reachableV[chargingS] == 1) ? 1 : 0;
    }
    return answer;
}
/*
using namespace std;
int main() {
	int n, m;
	assert(2 == scanf("%d %d", &n, &m));

	vector<int> a(n), r(n), u(m), v(m);

	for(int i = 0; i < n; i++)
		assert(1 == scanf("%d", &a[i]));

	for(int i = 0; i < n; i++)
		assert(1 == scanf("%d", &r[i]));

	for(int i = 0; i < m; i++)
		assert(2 == scanf("%d %d", &u[i], &v[i]));

	vector<int> res = who_wins(a, r, u, v);

	for(int i = 0; i < (int)res.size(); i++)
		printf(i ? " %d" : "%d", res[i]);
	printf("\n");

	return 0;
}
*/

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