Submission #713544

#	Time	Username	Problem	Language	Result	Execution time	Memory
713544		MohamedFaresNebili	Toy Train (IOI17_train)	C++14	0 / 100	2080 ms	262144 KiB

train

#include <bits/stdc++.h>

        using namespace std;

        int N, M, P[5001];
        int timer, tin[5001], low[5001];
        vector<int> adj[5001], G[5001], S;
        bool vis[5001], self[5001], Scc[5001], ST[5001];
        int station, reach[5001], DP[5001][5001];

        int findSet(int v) {
            if(P[v] == v) return v;
            return P[v] = findSet(P[v]);
        }
        bool sameSet(int u, int v) {
            return findSet(u) == findSet(v);
        }
        void unionSet(int u, int v) {
            u = findSet(u), v = findSet(v);
            if(u == v) return;
            P[u] = v;
        }

        void dfs(int v) {
            tin[v] = low[v] = timer++;
            vis[v] = 1; S.push_back(v);
            for(auto u : adj[v]) {
                if(tin[u] == -1) dfs(u);
                if(vis[u]) low[v] = min(low[v], low[u]);
            }
            if(tin[v] == low[v]) {
                vector<int> V;
                while(1) {
                    int U = S.back(); S.pop_back();
                    vis[U] = 0; V.push_back(U);
                    if(U == v) break;
                }
                if(V.size() == 1) return;
                for(int l = 1; l < V.size(); l++) {
                    unionSet(V[l], V[l - 1]);
                }
            }
        }
        int solve(int v, int t, int c, vector<int> A) {
            if(!reach[v]) return DP[v][t] = 0;
            if(DP[v][t] != -1) return DP[v][t];
            if(ST[v]) t = N;
            if(DP[v][t] != -1) return DP[v][t];
            if(v == station) c++;
            if(c == 2) return DP[v][t] = 1;
            if(t == 0) return DP[v][t] = 0;
            if(A[v] == 1) {
                if(self[v] && ST[v])
                    return DP[v][t] = 1;
                for(auto u : adj[v]) {
                    if(solve(u, t - 1, c, A))
                        return DP[v][t] = 1;
                }
                return DP[v][t] = 0;
            }
            if(A[v] == 0) {
                if(self[v] && !ST[v])
                    return DP[v][t] = 0;
                for(auto u : adj[v]) {
                    if(solve(u, t - 1, c, A) == 0)
                        return DP[v][t] = 0;
                }
                return DP[v][t] = 1;
            }
        }

        vector<int> who_wins(vector<int> A, vector<int> R,
                             vector<int> U, vector<int> V) {
            N = A.size(), M = U.size();
            for(int l = 0; l < N; l++) {
                ST[l] = R[l], P[l] = l;
                station = (ST[l] == 1 ? l : station);
            }
            for(int l = 0; l < M; l++) {
                int X = U[l], Y = V[l];
                if(X == Y) {
                    self[X] = 1;
                    if(ST[X] == 0) Scc[X] = 1;
                    continue;
                }
                adj[X].push_back(Y);
                G[Y].push_back(X);
            }
            memset(tin, -1, sizeof tin);
            memset(DP, -1, sizeof DP);
            for(int l = 0; l < N; l++) {
                if(tin[l] != -1) continue;
                dfs(l);
            }
            queue<pair<int, int>> q;
            vector<int> D(N, 1e9 + 7);
            q.push({station, 0}); D[station] = 0;
            while(!q.empty()) {
                int X = q.front().first;
                q.pop(); reach[X] = 1;
                for(auto Y : G[X]) {
                    if(D[X] + 1 < D[Y]) {
                        D[Y] = D[X] + 1;
                        q.push({Y, D[Y]});
                    }
                }
            }
            vector<int> res(N);
            for(int l = 0; l < N; l++)
                res[l] = solve(l, N, 0, A);
            return res;
        }

Compilation message (stderr)

train.cpp: In function 'void dfs(int)':
train.cpp:39:34: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |                 for(int l = 1; l < V.size(); l++) {
      |                                ~~^~~~~~~~~~
train.cpp: In function 'int solve(int, int, int, std::vector<int>)':
train.cpp:70:9: warning: control reaches end of non-void function [-Wreturn-type]
   70 |         }
      |         ^

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