Submission #885697

#	Time	Username	Problem	Language	Result	Execution time	Memory
885697		Kutan	Pipes (CEOI15_pipes)	C++17	50 / 100	777 ms	49612 KiB

pipes

// Cao Quang Hung
#include <cassert>
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>

using namespace std;
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define pii pair<int,int>
#define pll pair<long long , long long>
#define vi vector<int>
#define vpii vector<pii>
#define SZ(x) ((int)(x.size()))
#define fi first
#define se second
#define IN(x,y) ((y).find((x))!=(y).end())
#define ALL(t) t.begin(),t.end()
#define FOREACH(i,t) for (typeof(t.begin()) i=t.begin(); i!=t.end(); i++)
#define REP(i,a,b) for(int (i)=(a);(i)<=(b);++i)
#define REPD(i,a,b) for(int (i)=(a); (i)>=(b);--i)
#define FOR(i, n) for (int (i) = 0; (i) < (n); ++(i))
#define dem(x) __builtin_popcount(x)
#define Mask(x) (1LL << (x))
#define BIT(x, i) ((x) >> (i) & 1)
#define ln '\n'
#define io_faster ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
///mt19937 rnd(time(0));

const int INF = 1e9 , mod = 1e9 + 7;

template <class T1, class T2>
inline T1 mul(T1& x, const T2 &k){ return x = (1LL * x * k) % mod; }

template <class T1 , class T2>
inline T1 pw(T1 x, T2 k){T1 res = 1; for (; k ; k >>= 1){ if (k & 1) mul(res, x); mul(x, x); } return res;}

template <class T>
inline bool minimize(T &x, const T &y){ if (x > y){x = y; return 1;} return 0; }

template <class T>
inline bool maximize(T &x, const T &y){ if (x < y){x = y; return 1;} return 0; }

template <class T>
inline void add(T &x , const T &y){ if ((x += y) >= mod) x -= mod; }

template <class T>
inline T product (const T &x , const T &y) { return 1LL * x * y % mod; }

#define PROB "a"
void file(){
    if(fopen(PROB".inp", "r")){
        freopen(PROB".inp","r",stdin);
        freopen(PROB".out","w",stdout);
    }
}
void sinh_(){
//    srand(time(0));
//    freopen(PROB".inp" , "w" , stdout);
//    int n;
}

typedef long long ll;
typedef double db;
const int N = 1e5 + 2;

int n, m, u, v;
int par[N][17], depth[N], a[N] = {};

vi adj[N];
vpii Edge;

struct DSU{
    int par[N];
    int root(int x) {
        if (x == par[x]) return x;
        return par[x] = root(par[x]);
    }

    bool unite(int u, int v) {
        u = root(u), v = root(v);
        if (u == v) return 0;
        par[v] = u;
        return 1;
    }

    void init() {
        REP(i, 1, n) par[i] = i;
    }
} oneE, twoE;

void readip(){
    cin >> n >> m;   
    oneE.init();
    twoE.init();
    FOR(i, m) {
        cin >> u >> v;
        if (oneE.unite(u, v)) {
            adj[u].eb(v);
            adj[v].eb(u);
        }
        else if (twoE.unite(u, v)) Edge.eb(u, v);
    } 
}

void dfs_tree(int u, int p) {
    for (int &v : adj[u]) if (v != p) {
        depth[v] = depth[u] + 1;
        par[v][0] = u;
        REP(i, 1, 16) par[v][i] = par[par[v][i - 1]][i - 1];
        dfs_tree(v, u);
    }
}

int Lca(int u, int v) {
    if (depth[u] > depth[v]) swap(u, v);
    int dif = depth[v] - depth[u];
    REP(i, 0, 16) if (BIT(dif, i)) v = par[v][i];
    if (u == v) return u;
    REPD(i, 16, 0) if (par[v][i] != par[u][i])
        v = par[v][i] , u = par[u][i];
    return par[u][0];
}

void dfs(int u, int p) {
    for (int &v : adj[u]) if (v != p) {
        dfs(v, u);
        if (a[v] == 0) 
            cout << u << ' ' << v << ln;
        else 
            a[u] += a[v];
    }
}

void solve(){       
    REP(i, 1, n) if (oneE.root(i) == i) depth[i] = 0, dfs_tree(i, -1);

    for (const auto &[u, v] : Edge) {
        int anc = Lca(u, v);
        ++a[u], ++a[v];
        a[anc] -= 2;
    }

    REP(i, 1, n) if (oneE.root(i) == i) 
        dfs(i, -1);
}   

int main(){
    sinh_();
    io_faster
    file();
    int t = 1;
//    cin >> t;
    while (t--){
        readip();
        solve();
    }
}

Compilation message (stderr)

pipes.cpp: In member function 'void DSU::init()':
pipes.cpp:92:28: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   92 | #define REP(i,a,b) for(int (i)=(a);(i)<=(b);++i)
      |                            ^
pipes.cpp:160:9: note: in expansion of macro 'REP'
  160 |         REP(i, 1, n) par[i] = i;
      |         ^~~
pipes.cpp: In function 'void readip()':
pipes.cpp:94:28: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   94 | #define FOR(i, n) for (int (i) = 0; (i) < (n); ++(i))
      |                            ^
pipes.cpp:168:5: note: in expansion of macro 'FOR'
  168 |     FOR(i, m) {
      |     ^~~
pipes.cpp: In function 'void dfs_tree(int, int)':
pipes.cpp:92:28: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   92 | #define REP(i,a,b) for(int (i)=(a);(i)<=(b);++i)
      |                            ^
pipes.cpp:182:9: note: in expansion of macro 'REP'
  182 |         REP(i, 1, 16) par[v][i] = par[par[v][i - 1]][i - 1];
      |         ^~~
pipes.cpp: In function 'int Lca(int, int)':
pipes.cpp:92:28: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   92 | #define REP(i,a,b) for(int (i)=(a);(i)<=(b);++i)
      |                            ^
pipes.cpp:190:5: note: in expansion of macro 'REP'
  190 |     REP(i, 0, 16) if (BIT(dif, i)) v = par[v][i];
      |     ^~~
pipes.cpp:93:29: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   93 | #define REPD(i,a,b) for(int (i)=(a); (i)>=(b);--i)
      |                             ^
pipes.cpp:192:5: note: in expansion of macro 'REPD'
  192 |     REPD(i, 16, 0) if (par[v][i] != par[u][i])
      |     ^~~~
pipes.cpp: In function 'void solve()':
pipes.cpp:92:28: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   92 | #define REP(i,a,b) for(int (i)=(a);(i)<=(b);++i)
      |                            ^
pipes.cpp:208:5: note: in expansion of macro 'REP'
  208 |     REP(i, 1, n) if (oneE.root(i) == i) depth[i] = 0, dfs_tree(i, -1);
      |     ^~~
pipes.cpp:92:28: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   92 | #define REP(i,a,b) for(int (i)=(a);(i)<=(b);++i)
      |                            ^
pipes.cpp:216:5: note: in expansion of macro 'REP'
  216 |     REP(i, 1, n) if (oneE.root(i) == i)
      |     ^~~
pipes.cpp: In function 'void file()':
pipes.cpp:125:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  125 |         freopen(PROB".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
pipes.cpp:126:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  126 |         freopen(PROB".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10