Submission #1080136

#	Time	Username	Problem	Language	Result	Execution time	Memory
1080136		Ghulam_Junaid	Stations (IOI20_stations)	C++17	0 / 100	3 ms	1196 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);

    return val;
}

int find_next_station(int s, int t, vector<int> c){
    for (int i = 0; i + 1 < c.size(); i ++)
        assert(s > c[i]);
    assert(s < c.back());
    
    for (int x : c){
        if (t <= x){
            return x;
        }
    }
    int x = c.back();
    return x;
}

// 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)

stations.cpp: In function 'int find_next_station(int, int, std::vector<int>)':
stations.cpp:44:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |     for (int i = 0; i + 1 < c.size(); i ++)
      |                     ~~~~~~^~~~~~~~~~

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