Ice cream

#include <iostream>
#include <vector>
#include <set>

typedef long long LL;
using namespace std;

vector<bool> visited;
vector<int> colors;
vector<vector<int> > neighbors;

void dfs(int v, set<int>& colors_found, vector<int>& vertices_found){
    if(visited[v]) return;
    visited[v] = true;
    vertices_found.push_back(v);
    colors_found.insert(colors[v]);
    for(auto u : neighbors[v]){
        dfs(u, colors_found, vertices_found);
    }
}

int main(){
    int nVertices, nEdges;
    cin >> nVertices >> nEdges;
    for(int i = 0; i < nVertices; i++){
        int x; cin >> x; colors.push_back(x);
    }
    
    neighbors.resize(nVertices);
    for(int i = 0; i < nEdges; i++){
        int u,v; cin >> u >> v; u--; v--;
        neighbors[u].push_back(v);
        neighbors[v].push_back(u);
    }
    
    visited.resize(nVertices);
    vector<int> ans(nVertices);
        
    for(int v = 0; v < nVertices; v++){
        if(visited[v]) continue;
        
        set<int> colors_found;
        vector<int> vertices_found;
        vector<int> found;
        dfs(v, colors_found, vertices_found);
        for(auto u : vertices_found){
            ans[u] = colors_found.size();
        }
    }
    
    for(int i = 0; i < nVertices; i++){
        cout << ans[i] << " ";
    }
    cout << endl;
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

Verdict: ACCEPTED

Test 18

Verdict: ACCEPTED

Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED