Submission #1073168

#	Time	Username	Problem	Language	Result	Execution time	Memory
1073168		huyngodzz	Network (BOI15_net)	C++14	0 / 100	1 ms	6748 KiB

net

    ///huynhocute123///
#include<bits/stdc++.h>
using namespace std;
#define S second
#define F first
#define pii pair<int,int>
#define piii pair<int,pair<int,int>>
#define pb push_back
#define pi M_PI
#define FOR(i, a, b) for(int i = a; i <= b; ++i)
#define REP(i, a, b) for(int i = b; i >= a; --i)
#define ALL(v) v.begin(),v.end()
#define inp(name) if(fopen(name, "r")) freopen(name, "r", stdin);
#define out(name) if(fopen(name, "w")) freopen(name, "w", stdout);
//random_device rd;
//mt19937 rng(rd());
//#pragma GCC optimize ("O3")
//#pragma GCC optimize ("unroll-loops")
//#pragma GCC target("popcnt")
//#define int long long
const int maxN = 1e5 ;
const int  modd = 1e9 + 7;
const int base = 2309;
const int MAX = 1e9+9;
void minimize(int &u, int v){
    if(v < u) u = v;
}
void maximize(int &u, int v){
    if(v > u) u = v;
}
int n, k, t, m, res, a[maxN], low[maxN], nu[maxN], cnt, ck[maxN];
int l, r;
bool vis[maxN];
vector<int> e[maxN], adj[maxN];
vector<pii> bri;
void dfs(int u,int p ){
    nu[u] = low[u]= ++cnt;
    for(auto x : e[u]){
            if(x == p)continue;
        if(nu[x]){
            minimize(low[u], nu[x]);
        }else{
            dfs(x, u);
            minimize(low[u], low[x]);
            if(low[x] == nu[x]){
                adj[u].pb(x);
                adj[x].pb(u);
                ck[x] =1;
                ck[u] =1;
            }
        }

    }
}
void dfs2(int u ,int p){
    int ct = 0;
//    cout << u << " ";
    for(auto x : adj[u]){
        if(x == p)continue;
        vis[x] =1;
//        cout << x << " ";
        ct=1;
        dfs2(x, u);
//        maximize(k, max(ct- 1, 1))
    }
//    cout <<ct;
    if(ct == 0)++k;
}
void solve(){
    cin >> n >> m;
    FOR(i ,1 , m){
        cin >> l >> r;
        e[l].pb(r);
        e[r].pb(l);
    }
    FOR(i, 1, n){
    if(!nu[i])dfs(i,0);
    }
    FOR(i ,1 , n){
        if(!vis[i]  && ck[i] ==1 ){
            k =0;
            vis[i] =1;
            dfs2(i, 0);
            if(adj[i].size() == 1)k++;
//            cout << k <<  " ";
               res += (k + 1 )/2;
//            res +=k;
        }
    }
    cout <<res;
//    for(auto [x,y] : bri){
//            cout << x << "     " << y <<'\n';
//    }
//    cout << bri.size();

}
signed main(){
//    freopen("name.inp","r",stdin);
//    freopen("name.out","w",stdout);
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    inp("task.inp");
    t = 1;
   // cin >> t;
    while( t-- )solve();

}

Compilation message (stderr)

net.cpp: In function 'int main()':
net.cpp:13:47: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 | #define inp(name) if(fopen(name, "r")) freopen(name, "r", stdin);
      |                                        ~~~~~~~^~~~~~~~~~~~~~~~~~
net.cpp:102:5: note: in expansion of macro 'inp'
  102 |     inp("task.inp");
      |     ^~~

• Subtask 1: 0 / 18
• Subtask 2: 0 / 45
• Subtask 3: 0 / 37