Submission #540695

#	Time	Username	Problem	Language	Result	Execution time	Memory
540695		Vladth11	Pipes (CEOI15_pipes)	C++14	100 / 100	1058 ms	14284 KiB

pipes

#include <iostream>
#include <map>
#include <vector>

using namespace std;

const int NMAX = 100001;

vector <int> v[NMAX];
int root;
int lvl[NMAX];
int parent[NMAX];
int parentB[NMAX];

int findR(int a){
    if(parent[a] == a)
        return a;
    return parent[a] = findR(parent[a]);
}

int findRB(int a){
    if(parentB[a] == a)
        return a;
    return parentB[a] = findRB(parentB[a]);
}

void unite(int a, int b){
    a = findR(a);
    b = findR(b);
    parent[a] = b;
}

void uniteB(int a, int b){
    a = findRB(a);
    b = findRB(b);
    parentB[a] = b;
}

map <int, int> dp;

void DFS(int node, int p){
    lvl[node] = lvl[p] + 1;
    for(auto x : v[node]){
        if(lvl[x] == 0){
            DFS(x, node);
        }else if(lvl[x] > lvl[node]){
            dp[node]--;
        }else{
            dp[node]++;
        }
    }
    if(node != root){
        dp[node]--;
    }
    dp[p] += dp[node];
    if(dp[node] == 0 && node != root){
        cout << node << " " << p << "\n";
    }
  dp.erase(node);

}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n, m, i;
    cin >> n >> m;
    for(i = 1; i <= n; i++){
        parent[i] = i;
        parentB[i] = i;
    }
    for(i = 1; i <= m; i++){
        int a, b;
        cin >> a >> b;
        if(findR(a) != findR(b)){
            v[a].push_back(b);
            v[b].push_back(a);
            unite(a, b);
        }else if(findRB(a) != findRB(b)){
            v[a].push_back(b);
            v[b].push_back(a);
            uniteB(a, b);
        }
    }
    for(i = 1; i <= n; i++){
        if(!lvl[i]){
            root = i;
            DFS(root, 0);
        }
    }
    return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10