Submission #144938

#	Time	Username	Problem	Language	Result	Execution time	Memory
144938		Abelyan	Zagrade (COI17_zagrade)	C++17	10 / 100	1480 ms	47628 KiB

zagrade

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

#define FOR(i,a) for (int i=0;i<(a);++i)
#define FORD(i,a) for (int i=(a)-1;i>=0;i--)
#define FORT(i,a,b) for (int i=(a);i<=(b);++i)
#define FORTD(i,b,a) for (int i=(b);i>=(a);--i)
#define trav(i,v) for (auto i : v)
#define all(v) v.begin(),v.end()
#define ad push_back
#define fr first
#define sc second
#define mpr(a,b) make_pair(a,b)
#define pir pair<int,int>
#define all(v) v.begin(),v.end()
#define make_unique(v) v.erase(unique(all(v)),v.end())
#define fastio ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define srng mt19937 rng(chrono::steady_clock::now().time_since_epoch().count())
#define y1 EsiHancagorcRepa

const int N=4e5+10;
const ll MOD2=998244353;
const ll MOD=1e9+7;

char c[N];
int qan=0;
vector<int> g[N],vc;
int sz[N],ans;
bool col[N];

void dfssz(int v,int par=-1){
    sz[v]=1;
    qan++;
    trav(to,g[v]){
        if (col[to] || to==par) continue;
        dfssz(to,v);
        sz[v]+=sz[to];
    }
}

int get(int v,int par=-1){
    trav(to,g[v]){
        if (col[to] || to==par) continue;
        if (sz[to]>qan/2) return get(to,v);
    }
    return v;
}

set<pir> s;
set<pir>::iterator it;

void dfs1(int v,int pr,int mn,int par=-1){
    //if (v==3)cout<<v<<" "<<pr<<" "<<mn<<endl;
    if (c[v]=='('){
        pr++;
        mn++;
        mn=min(mn,1);
    }
    else{
        pr--;
        mn--;
        mn=min(mn,-1);
    }
    //if (v==3)cout<<v<<" "<<pr<<" "<<mn<<endl;
    if (mn>=0){
        it=s.lower_bound({pr,INT_MIN});
        if (it==s.end() || it->fr!=pr){
            s.insert({pr,1});
            //cout<<v<<" "<<pr<<endl;
        }
        else{
            pir tv=*it;
            tv.sc++;
            s.erase(it);
            s.insert(tv);
            //cout<<pr<<endl;
        }
    }
    trav(to,g[v])if (!col[to] && par!=to)dfs1(to,pr,mn,v);
}

void dfs2(int v,int pr,int mn,int par=-1){
    if (c[v]=='('){
        pr++;
    }
    else{
        pr--;
    }
    mn=min(mn,pr);
    if (mn==pr){
        vc.ad(pr);
        //cout<<"hey "<<pr<<endl;
    }
    trav(to,g[v])if (!col[to] && par!=to)dfs2(to,pr,mn,v);
}


void decomp(int v){
    qan=0;
    dfssz(v);
    int cent=get(v);
    //cout<<cent<<endl;
    FOR(i,g[cent].size()){
        int to=g[cent][i];
        if (col[to])continue;
        dfs2(to,0,0,cent);
        trav(tv,vc){
            it=s.lower_bound({-tv,INT_MIN});
            if (it->fr==-tv){
                ans+=it->sc;
            }
        }
        vc.clear();
        if (c[cent]=='(')
            dfs1(to,1,1,cent);
        else dfs1(to,-1,-1,cent);
    }
    while(!s.empty())s.erase(s.begin());
    if (c[cent]=='(')s.insert({1,1});
    FORD(i,g[cent].size()){
        int to=g[cent][i];
        if (col[to])continue;
        dfs2(to,0,0,cent);
        trav(tv,vc){
            //if (c[cent]=='C' && tv==-1)ans++;
            it=s.lower_bound({-tv,INT_MIN});
            if (it->fr==-tv){
                ans+=it->sc;
            }
        }
        vc.clear();
        if (c[cent]=='(')
            dfs1(to,1,1,cent);
        else dfs1(to,-1,-1,cent);
    }
    it=s.lower_bound({0,INT_MIN});
    //cout<<cent<<" "<<ans<<endl;
    if (it->fr==0){
        ans+=it->sc;
    }
    while(!s.empty())s.erase(s.begin());
    col[cent]=true;
    trav(to,g[cent]){
        if (!col[to])decomp(to);
    }
}

int main(){
    fastio;
    srng;
    #ifdef ALEXPC
    freopen("input.txt","r",stdin);
    freopen("output.txt","w",stdout);
    #endif
    int n;
    cin>>n;
    assert(n>=10);
    FORT(i,1,n){
        cin>>c[i];
    }
    FOR(i,n-1){
        int a,b;
        cin>>a>>b;
        g[a].ad(b);
        g[b].ad(a);
    }
    decomp(1);
    cout<<ans<<endl;
    return 0;
}

Compilation message (stderr)

zagrade.cpp: In function 'void decomp(int)':
zagrade.cpp:8:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
 #define FOR(i,a) for (int i=0;i<(a);++i)
                                ^
zagrade.cpp:107:5: note: in expansion of macro 'FOR'
     FOR(i,g[cent].size()){
     ^~~

• Subtask 1: 10 / 10
• Subtask 2: 0 / 30
• Subtask 3: 0 / 60