Submission #472459

#	Time	Username	Problem	Language	Result	Execution time	Memory
472459		yasseenkamel	Railway (BOI17_railway)	C++14	8 / 100	1090 ms	31480 KiB

railway

#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")
#pragma GCC optimize("-Ofast")
#include <bits/stdc++.h>

using namespace std;

typedef int in;
#define int long long
#define s second
#define f first
const long double EPS=1e-9;
const int MOD=1e9+7;
const int N=1e6;

int n,m,k;
vector<int> adj[100005];
map<pair<int,int>,int> ed;
bool b = 0;
int f[100005];
bool vis[100006],tar[10005];

int dfs(int node,int par){
    vis[node] = 1;
    int ret = 0;
    if(tar[node]){
        ret = 1;
    }
    for(int i = 0 ; i < adj[node].size() ; i ++){
        int f1 = adj[node][i];
        if(f1 == par){
            continue;
        }
        int ans = dfs(f1,node);
        f[ed[{node,f1}]] += ans;
        ret = max(ret,ans);
    }
    return ret;
}

in main(){
	cin >> n >> m >> k;
	for(int i = 0 ; i < n - 1 ; i ++){
        int x,y;
        cin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
        ed[{x,y}] = i + 1;
        ed[{y,x}] = i + 1;
	}
	for(int i = 0 ; i < m ; i ++){
        int x,y;
        cin >> x >> y;
        memset(tar,0,sizeof tar);
        for(int j = 1 ; j < x ; j ++){
            int z;
            cin >> z;
            tar[z] = 1;
        }
        dfs(y,-1);
	}
	vector<int> v;
	for(int i = 1 ; i <= n ; i ++){
        //cout << f[i] << endl;
        if(f[i] >= k){
            v.push_back(i);
        }
	}
	cout << v.size() << endl;
	for(int i = 0 ; i < v.size() ; i ++){
        cout << v[i] << " ";
	}
    return 0;
}

Compilation message (stderr)

railway.cpp: In function 'long long int dfs(long long int, long long int)':
railway.cpp:29:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |     for(int i = 0 ; i < adj[node].size() ; i ++){
      |                     ~~^~~~~~~~~~~~~~~~~~
railway.cpp: In function 'in main()':
railway.cpp:70:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   70 |  for(int i = 0 ; i < v.size() ; i ++){
      |                  ~~^~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 0 / 15
• Subtask 3: 0 / 7
• Subtask 4: 0 / 29
• Subtask 5: 0 / 16
• Subtask 6: 0 / 25