Submission #472437

#	Time	Username	Problem	Language	Result	Execution time	Memory
472437		yasseenkamel	Railway (BOI17_railway)	C++14	0 / 100	1081 ms	33360 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,tar;
vector<int> adj[100005];
map<pair<int,int>,int> ed;
bool b = 0;
int f[100005];

void dfs(int node,int par){
    if(b || node == tar){
        b = 1;
        return;
    }
    for(int i = 0 ; i < adj[node].size() ; i ++){
        int f1 = adj[node][i];
        if(f1 == par){
            continue;
        }
        int idx = ed[{node,f1}];
        f[idx] ++;
        dfs(f1,node);
        if(b){
            return;
        }
        f[ed[{node,f1}]] -= (!b);
    }
}

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;
        cin >> x >> y;
        b = 0;
        tar = y;
        dfs(x,-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 'void dfs(long long int, long long int)':
railway.cpp:27:23: 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]
   27 |     for(int i = 0 ; i < adj[node].size() ; i ++){
      |                     ~~^~~~~~~~~~~~~~~~~~
railway.cpp: In function 'in main()':
railway.cpp:68:20: 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]
   68 |  for(int i = 0 ; i < v.size() ; i ++){
      |                  ~~^~~~~~~~~~

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