Submission #1359475

#	Time	Username	Problem	Language	Result	Execution time	Memory
1359475		opeleklanos	Thousands Islands (IOI22_islands)	C++20	Compilation error	0 ms	0 KiB

islands

#include <iostream>
#include <vector>
#include <variant>
#include <algorithm>
#include <stack>
using namespace std;

vector<vector<pair<int, int>>> adj;
vector<int> vis;
vector<int> tpsort;
vector<int> path;

stack<int> s;


int findPath(int st){
    if(vis[st]){
        vector<int> nodesInCycle;
        while(s.top() != st) nodesInCycle.push_back(s.top());

        int curr = st;
        path.push_back(st);
        for(auto i : nodesInCycle){
            path.push_back(i);
        }
        path.push_back(st);
        for(auto i : nodesInCycle){
            path.push_back(i);
        }
        path.push_back(st);
        reverse(nodesInCycle.begin(), nodesInCycle.end());
        for(auto i : nodesInCycle) path.push_back(i);
        path.push_back(st);
        for(auto i : nodesInCycle) path.push_back(i);
        path.push_back(st);
        return 1;
    }

    vis[st] = 1;
    s.push(st);
    path.push_back(st);
    int found = 0;
    for(auto i : adj[st]) if(findPath(st)) found = 1;

    if(!found) path.pop_back();
    else path.push_back(st);
    s.pop();

    return found;
}

void dfs(int st){
    vis[st] = 1;
    for(auto c : adj[st]) if(!vis[c.first]) dfs(c.first);

    tpsort.push_back(st);
}

vector<int> buildPath(){
    vector<int> ret;
    for(int i = 0; i<path.size()-1; i++){
        int f = 0;
        for(int j = 0; j<adj[path[i]].size(); j++){
            if(adj[path[i]][j].first == path[i+1] && adj[path[i]][j].second > 0){
                ret.push_back(adj[path[i]][j].second);
                adj[path[i]][j].second = -adj[path[i]][j].second;
                f = 1;
                break;
            } 
        }
        if(f == 1) continue;
        for(int j = 0; j<adj[path[i+1]].size(); j++){
            if(adj[path[i+1]][j].first == path[i] && adj[path[i]][j].second < 0){
                ret.push_back(-adj[path[i+1]][j].second);
                adj[path[i+1]][j].second = -adj[path[i+1]][j].second;
                f = 1;
                break;
            } 
        }
    }
    return ret;
}

variant<bool, vector<int>> find_journey(int N, int M, vector<int> U, vector<int> V){

    adj.assign(N, {});
    vis.assign(N, 0);
    tpsort.assign(0, 0);

    goesTo.assign()

    for(int i = 0; i<M; i++){
        adj[U[i]].push_back({V[i], i});
    }

    dfs(0);

    reverse(tpsort.begin(), tpsort.end());
    vector<int> indx(N, -1);
    for(int i = 0; i<tpsort.size(); i++) indx[tpsort[i]] = i;

    for(int i = 0; i<N; i++){
        if(!vis[i]) continue;
        for(auto j : adj[i]){
            if(indx[i] > indx[j.first]){
                path.assign(0, 0);
                vis.assign(N, 0);
                findPath(0);
                return buildPath();
            }
        }
    }

    return (bool)0;
}

Compilation message (stderr)

islands.cpp: In function 'std::variant<bool, std::vector<int, std::allocator<int> > > find_journey(int, int, std::vector<int>, std::vector<int>)':
islands.cpp:90:5: error: 'goesTo' was not declared in this scope
   90 |     goesTo.assign()
      |     ^~~~~~
islands.cpp:92:20: error: 'i' was not declared in this scope
   92 |     for(int i = 0; i<M; i++){
      |                    ^