Submission #208320

#	Time	Username	Problem	Language	Result	Execution time	Memory
208320		rzbt	Zagrade (COI17_zagrade)	C++14	100 / 100	697 ms	50852 KiB

zagrade

#include <bits/stdc++.h>
#define pb push_back
#define mp make_pair
#define all(x) x.begin(),x.end()
#define F first
#define S second
#define MAXN 300005
using namespace std;
typedef long long ll;
ll n;
char s[MAXN];
ll zagrada[MAXN];
vector<ll> niz[MAXN];
ll obradjen[MAXN];
ll podst[MAXN];
ll cale[MAXN];
ll neg[MAXN],poz[MAXN];
ll res=0;
vector<ll> dodaj;
ll dfsV(ll t,ll o){
    podst[t]=1;
    cale[t]=o;
    for(auto x:niz[t])
        if(x!=o && !obradjen[x])
            podst[t]+=dfsV(x,t);
    return podst[t];
}


void dfsR(ll t,ll o,ll mi,ll ma,ll vkorena,ll vrednost){
    vrednost+=zagrada[t];
    if(vrednost>0 && ma<=vrednost){
        //if(neg[vrednost])printf("k     %lld %lld\n",t,vrednost);
        res+=neg[vrednost];
        dodaj.pb(vrednost-vkorena);
    }
    if(vrednost<0 && mi>=vrednost){
        //if(poz[-vrednost])printf("k     %lld %lld\n",t,vrednost);
        res+=poz[-vrednost];
        dodaj.pb(vrednost-vkorena);
    }
    if(vrednost==0){
        if(mi==0){
            //printf("dodao   %lld\n",t);
            res+=1+(neg[0]+poz[0]);
            dodaj.pb(-1);
        }
        if(ma==0){
            //printf("dodao  %lld\n",t);

            res+=1+(neg[0]+poz[0]);
            dodaj.pb(1);
        }

    }
    for(auto x:niz[t]){
        if(obradjen[x]|| x==o)continue;
        dfsR(x,t,min(mi,vrednost),max(ma,vrednost),vkorena,vrednost);
    }

}


void centroidna(ll c){

    dfsV(c,0);
    ll vel=podst[c];
    for(ll i=0;i<=vel+1;i++){
        neg[i]=0;
        poz[i]=0;
    }
    if(vel==1){
        //printf("    jedan %lld\n",c);
        obradjen[c]=true;
        return;
    }
    while(22){
        bool naso=false;
        for(auto x:niz[c]){
            if(obradjen[x] || x==cale[c])continue;
            if(podst[x]>(vel>>1)){
                c=x;
                naso=true;
                break;
            }
        }
        if(!naso)break;
    }
    /// OVDE IDE OBRADA
    for(auto x:niz[c]){
        if(obradjen[x])continue;
        dfsR(x,c,min(0ll,zagrada[c]),max(0ll,zagrada[c]),zagrada[c],zagrada[c]);
        for(auto y:dodaj){
            if(y>=0)poz[y]++;
            else neg[-y]++;
        }
        dodaj.clear();
    }

    ///OVDE JE KRAJ OBRADE
    //printf("    %lld  %lld\n",c,res);
    obradjen[c]=true;
    for(auto x:niz[c]){
        if(!obradjen[x])centroidna(x);
    }
}


int main()
{
    scanf("%lld", &n);
    scanf("%s",s);
    for(ll i=1;i<=n;i++)
        zagrada[i]=(s[i-1]=='('?1:-1);
    for(ll i=1;i<n;i++){
        ll t1,t2;
        scanf("%lld %lld", &t1, &t2);
        niz[t1].pb(t2);
        niz[t2].pb(t1);
    }

    centroidna(1);
    printf("%lld",res);
    return 0;
}

Compilation message (stderr)

zagrade.cpp: In function 'int main()':
zagrade.cpp:111:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%lld", &n);
     ~~~~~^~~~~~~~~~~~
zagrade.cpp:112:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%s",s);
     ~~~~~^~~~~~~~
zagrade.cpp:117:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld %lld", &t1, &t2);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 30 / 30
• Subtask 3: 60 / 60