Submission #1080119

#	Time	Username	Problem	Language	Result	Execution time	Memory
1080119		Ghulam_Junaid	Stations (IOI20_stations)	C++17	0 / 100	603 ms	940 KiB

stations

#include <bits/stdc++.h>
using namespace std;

const int N = 1005;
int sz[N], pref[N];
vector<int> val, g[N];

void pre_dfs(int v, int p = -1){
    sz[v] = 1;
    for (int u : g[v]){
        if (u == p) continue;
        pre_dfs(u, v);
        sz[v] += sz[u];
    }
}

void dfs(int v, int p = -1){
    pref[v] = 0;
    for (int u : g[v]){
        if (u == p) continue;
        pref[v] += sz[u];
        val[u] = val[v] - sz[v] + pref[v];
        dfs(u, v);
    }
}

vector<int> label(int n, int k, vector<int> u, vector<int> v){
    for (int i = 0; i <= n; i ++)
        pref[i] = sz[i] = 0, g[i].clear();

    val.resize(n, 0);
    for (int i = 0; i < n - 1; i ++){
        g[u[i]].push_back(v[i]);
        g[v[i]].push_back(u[i]);
    }
    pre_dfs(0);
    val[0] = sz[0];
    dfs(0);

    set<int> st;
    for (int x : val)
        st.insert(x);
    assert(st.size() == n);
    return val;
}

int find_next_station(int s, int t, vector<int> c){
    // cout << s << " ?? " << t << endl;
    for (int x : c){
        // cout << "cmp " << x << endl;
        if (t <= x){
            // cout << "goto " << x << endl;
            return x;
        }
    }
    // cout << "goto " << c.back() << endl;
    return c.back();
}

// int main(){
//     int t;
//     cin >> t;
//     while (t--){
//         int n, k;
//         cin >> n >> k;
//         vector<int> u(n - 1), v(n - 1);

//         for (int i = 0; i < n - 1; i ++)
//             cin >> u[i] >> v[i];
//         label(n, k, u, v);
//         for (int i = 0; i < n; i ++){
//             cout << i << " :: " << val[i] << endl;
//         }

//         for (int i = 0; i < n; i ++){
//             for (int j = 0; j < n; j ++){
//                 if (i == j) continue;

//                 vector<int> adj;
//                 for (int x : g[i])
//                     adj.push_back(val[x]);
//                 sort(adj.begin(), adj.end());

//                 int res = find_next_station(val[i], val[j], adj);
//                 cout << val[i] << " -- " << val[j] << " == " << res << endl;
//             }
//         }
//     }
// }

/*

10 10
0 1 
1 2
2 3
3 4
4 5
5 6
6 7
7 8
8 9

*/

Compilation message (stderr)

In file included from /usr/include/c++/10/cassert:44,
                 from /usr/include/x86_64-linux-gnu/c++/10/bits/stdc++.h:33,
                 from stations.cpp:1:
stations.cpp: In function 'std::vector<int> label(int, int, std::vector<int>, std::vector<int>)':
stations.cpp:43:22: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   43 |     assert(st.size() == n);
      |            ~~~~~~~~~~^~~~

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