Submission #361939

#	Time	Username	Problem	Language	Result	Execution time	Memory
361939		valerikk	Stations (IOI20_stations)	C++14	10 / 100	1010 ms	55732 KiB

stations

#include <vector>
using namespace std;

const int N = 1e6 + 7;
vector<int> g[N];
int tin[N], tout[N], t;

void dfs(int v, int p = -1) {
    tin[v] = t++;
    for (int u : g[v]) {
        if (u != p) dfs(u, v);
    }
    tout[v] = t;
}

vector<int> label(int n, int k, vector<int> u, vector<int> v) {
    for (int i = 0; i < n; i++) g[i].clear();
    for (int i = 0; i < n - 1; i++) {
        g[u[i]].push_back(v[i]);
        g[v[i]].push_back(u[i]);
    }
    t = 0;
    dfs(0);
    tout[0] = n - 1;
    vector<int> l(n);
    for (int i = 0; i < n; i++) l[i] = tin[i]*1000 + tout[i];
    return l;
}

void f(int v) {
    tin[v] = v / 1000;
    tout[v] = v % 1000;
    if (tin[v] == 0) tout[v]++;
}

int find_next_station(int s, int t, vector<int> c) {
    f(s); f(t);
    for (int v : c) f(v);
    int p;
    for (int v : c) {
        if (tin[v] <= tin[s] && tout[v] >= tout[s]) {
            p = v;
            continue;
        }
        if (tin[v] <= tin[t] && tout[v] >= tout[t]) return v;
    }
    return p;
}

Compilation message (stderr)

stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:39:9: warning: 'p' may be used uninitialized in this function [-Wmaybe-uninitialized]
   39 |     int p;
      |         ^

• Subtask 1: 0 / 5
• Subtask 2: 0 / 8
• Subtask 3: 0 / 16
• Subtask 4: 10 / 10
• Subtask 5: 0 / 61