Submission #1278533

#	Time	Username	Problem	Language	Result	Execution time	Memory
1278533		longdeptrai	Power Plant (JOI20_power)	C++20	100 / 100	74 ms	26260 KiB

power

#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
//using namespace __gnu_pbds;
#define LongDepTrai "pow_plant"
#define ll long long
#define ull unsigned long long
#define ld long double
#define ii pair<int,int>
#define iii pair<int,ii>
#define iv pair<ii,ii>
#define pll pair<ll,ll>
#define vi vector<int>
#define vii vector<ii>
#define vll vector<ll>
#define fi first
#define se second
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define sz(x) int((x).size())
#define order_set(T) tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>

inline ll add(ll a, ll b, ll mod){ a += b; if(a >= mod) a -= mod; return a; }
inline ll sub(ll a, ll b, ll mod){ a -= b; if(a < 0) a += mod; return a; }
inline ll mul(ll a, ll b, ll mod){ return ( (ll)a * b ) % mod; }

static mt19937_64 rng((unsigned)chrono::steady_clock::now().time_since_epoch().count());
const int N=2e5+9;
int n,f[N],res=0;
//f[u]:so nhanh chua may phat trong u.
vi g[N];
string a;
void dfs(int u,int p){
    for(int x:g[u]){
        if(x==p) continue;
        dfs(x,u);
        if(a[u]=='1') res=max(res,f[x]+1);
        f[u]+=f[x];
    }
    if(a[u]=='1')f[u]=max(f[u]-1,1);
    res=max(res,f[u]);
}
signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);

    if(fopen(LongDepTrai".inp","r")){
        freopen(LongDepTrai".inp","r",stdin);
        freopen(LongDepTrai".out","w",stdout);
    }

    cin>>n;
    for(int i=1;i<n;i++){
        int u,v;
        cin>>u>>v;
        g[u].pb(v);
        g[v].pb(u);
    }
    cin>>a;
    a=" "+a;
    dfs(1,-1);
    cout<<res;


    return 0;
}

Compilation message (stderr)

power.cpp: In function 'int main()':
power.cpp:49:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |         freopen(LongDepTrai".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
power.cpp:50:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   50 |         freopen(LongDepTrai".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 41 / 41
• Subtask 3: 53 / 53