Submission #669381

#	Time	Username	Problem	Language	Result	Execution time	Memory
669381		ShaShi	Pipes (CEOI15_pipes)	C++17	100 / 100	978 ms	16216 KiB

pipes

#include <bits/stdc++.h>
#define lint long long int
#define dint long double
#define ll long long
#define endl "\n"
#define pii pair<int, int>
#define pb push_back
#define F first
#define S second

using namespace std;

const int MOD = (int)1e9 + 23;
const int MAXN = (int)1e5 + 23;
const int MAX_LOG = 17 + 1;
const int INF = (int)1e9 + 23;

int n, m, tmp, tmp2, u, v;
int par1[MAXN], par2[MAXN], sz1[MAXN], sz2[MAXN], h[MAXN], dp[MAXN], googool[MAXN+MAXN], p[MAXN];
vector<pii> adj[MAXN];
bool seen[MAXN];

int get_par1(int v) {
    return (par1[v] == -1? v : par1[v] = get_par1(par1[v]));
}

int get_par2(int v) {
    return (par2[v] == -1? v : par2[v] = get_par2(par2[v]));
}

bool merge1(int u, int v) {
    u = get_par1(u);
    v = get_par1(v);

    if (u == v) return 0;

    par1[u] = v;

    return 1;
}

bool merge2(int u, int v) {
    u = get_par2(u);
    v = get_par2(v);

    if (u == v) return 0;

    par2[u] = v;

    return 1;
}

void DFS(int v) {
	seen[v] = 1;

	for(auto w:adj[v]) {
        int u = w.F;
        int ind=w.S;
        
        if(seen[u]){
			if(googool[ind] == 0 && h[u] < (h[v])){
				dp[v]++;
				dp[u]--;
			}
			continue;
		}

		h[u] = h[v] + 1; 
		p[u] = v;
		googool[ind] = 1; 
		DFS(u);
		dp[v] += dp[u];
	}
}

int32_t main() {
	ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    
    cin >> n >> m;

    fill(par1, par1+n+1, -1);
    fill(par2, par2+n+1, -1);
    tmp = 1;

    for (int i=1; i<=m; i++) {
        cin >> u >> v;

        if (merge1(u, v)) {
            adj[u].pb({v, tmp});
            adj[v].pb({u, tmp});
            tmp++;
        } else if (merge2(u, v)) {
            adj[u].pb({v, tmp});
            adj[v].pb({u, tmp});
            tmp++;
        }
    }

    for (int i=1; i<=n; i++) {
        if (!seen[i]) {
            DFS(i);
        }
    }

    for (int i=1; i<=n ; i++) {
		if (!dp[i] && p[i]) {
			cout << p[i] << " " << i << endl;
		}
	}

    
    


    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