Submission #1293835

#	Time	Username	Problem	Language	Result	Execution time	Memory
1293835		123123123	World Map (IOI25_worldmap)	C++20	Compilation error	0 ms	0 KiB

worldmap

#include <bits/stdc++.h>
using namespace std;
vector<vector<int>> adj;
vector<bool> used;
vector<int> tour;
void DFS(int v) {
    used[v] = true;
    tour.push_back(v);
    for(int to : adj[v]) {
        if(!used[to]) {
            DFS(to);
            tour.push_back(v); 
        }
    }
}

vector<vector<int>> create_map(int N, int M, vector<int> A, vector<int> B) {
    if(M == 0) return {{1}}; 

    adj.assign(N + 1, {});
    used.assign(N + 1, false);
    tour.clear();

    for(int i = 0; i < M; i++) {
        adj[A[i]].push_back(B[i]);
        adj[B[i]].push_back(A[i]);
    }

    vector<bool> vis(N + 1, false);
    queue<int> q;
    q.push(1);
    vis[1] = true;
    vector<vector<int>> treeAdj(N + 1);

    while(!q.empty()) {
        int v = q.front(); q.pop();
        for(int to : adj[v]) {
            if(!vis[to]) {
                vis[to] = true;
                q.push(to);
                treeAdj[v].push_back(to);
                treeAdj[to].push_back(v);
            }
        }
    }

    adj = treeAdj;
    DFS(1);     

    int rows = 4 * N;
    int cols = 4 * N;
    vector<vector<int>> mymap(rows, vector<int>(cols, 0));
    int curRow = 0;
    map<int,int> firstOcc;

    for(int node : tour) {
        if(!firstOcc.count(node)) {
            firstOcc[node] = curRow++;
            int r1 = curRow++;
            int r2 = curRow++;

            for(int j = 0; j < cols; j++) mymap[r2][j] = node;

            int col = 0;
            for(int nei : adj[node]) {
                if(col >= cols) break;
                mymap[r1][col++] = node;
                if(col >= cols) break;
                mymap[r1][col++] = nei;
            }
        }
    }

    for(int i = 1; i < rows; i++)
        for(int j = 0; j < cols; j++)
            if(mymap[i][j] == 0)
                mymap[i][j] = mymap[i-1][j];

    return mymap;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N, M;
    cin >> N >> M;
    vector<int> A(M), B(M);
    for(int i = 0; i < M; i++) cin >> A[i];
    for(int i = 0; i < M; i++) cin >> B[i];

    vector<vector<int>> grid = create_map(N, M, A, B);

    for(auto &row : grid) {
        for(int j = 0; j < (int)row.size(); j++) {
            cout << row[j];
            if(j + 1 < (int)row.size()) cout << " ";
        }
        cout << "\n";
    }
}

Compilation message (stderr)

/usr/bin/ld: /tmp/ccR7gesj.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccEHz1fh.o:worldmap.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status