Submission #1318855

#	Time	Username	Problem	Language	Result	Execution time	Memory
1318855		g31nius	Easter Eggs (info1cup17_eastereggs)	C++20	Compilation error	0 ms	0 KiB

eastereggs

#include <vector>
using namespace std;

int query(vector<int> islands);  // Declaration of the grader's function

int findEgg(int N, vector<pair<int, int>> bridges) {
    // Build adjacency list
    vector<vector<int>> adj(N + 1);
    for (auto& edge : bridges) {
        adj[edge.first].push_back(edge.second);
        adj[edge.second].push_back(edge.first);
    }
    
    // Binary search approach on the tree
    // Start from node 1 and traverse the tree
    int current = 1;
    
    while (true) {
        // Check each subtree of current node
        bool found = false;
        
        for (int neighbor : adj[current]) {
            // Get all nodes in this subtree (excluding parent path)
            vector<int> subtree;
            vector<bool> visited(N + 1, false);
            
            // DFS to collect subtree nodes
            function<void(int, int)> dfs = [&](int node, int parent) {
                visited[node] = true;
                subtree.push_back(node);
                for (int next : adj[node]) {
                    if (next != parent && !visited[next]) {
                        dfs(next, node);
                    }
                }
            };
            
            dfs(neighbor, current);
            
            // Query this subtree
            if (query(subtree) == 1) {
                current = neighbor;
                found = true;
                break;
            }
        }
        
        // If no subtree contains the egg, it must be at current node
        if (!found) {
            return current;
        }
    }
}

Compilation message (stderr)

eastereggs.cpp: In function 'int findEgg(int, std::vector<std::pair<int, int> >)':
eastereggs.cpp:28:13: error: 'function' was not declared in this scope
   28 |             function<void(int, int)> dfs = [&](int node, int parent) {
      |             ^~~~~~~~
eastereggs.cpp:2:1: note: 'std::function' is defined in header '<functional>'; did you forget to '#include <functional>'?
    1 | #include <vector>
  +++ |+#include <functional>
    2 | using namespace std;
eastereggs.cpp:28:35: error: expression list treated as compound expression in functional cast [-fpermissive]
   28 |             function<void(int, int)> dfs = [&](int node, int parent) {
      |                                   ^
eastereggs.cpp:28:22: error: expected primary-expression before 'void'
   28 |             function<void(int, int)> dfs = [&](int node, int parent) {
      |                      ^~~~
eastereggs.cpp:38:13: error: 'dfs' was not declared in this scope
   38 |             dfs(neighbor, current);
      |             ^~~