Submission #173549

#	Time	Username	Problem	Language	Result	Execution time	Memory
173549		nikolapesic2802	Election (BOI18_election)	C++14	0 / 100	55 ms	37624 KiB

election

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/rope>

#define ll long long
#define pb push_back
#define sz(x) (int)(x).size()
#define mp make_pair
#define f first
#define s second
#define all(x) x.begin(), x.end()
#define D(x) cerr << #x << " is " << (x) << "\n";

using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
template<class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>; ///find_by_order(),order_of_key()
template<class T1, class T2> ostream& operator<<(ostream& os, const pair<T1,T2>& a) { os << '{' << a.f << ", " << a.s << '}'; return os; }
template<class T> ostream& operator<<(ostream& os, const vector<T>& a){os << '{';for(int i=0;i<sz(a);i++){if(i>0&&i<sz(a))os << ", ";os << a[i];}os<<'}';return os;}
template<class T> ostream& operator<<(ostream& os, const deque<T>& a){os << '{';for(int i=0;i<sz(a);i++){if(i>0&&i<sz(a))os << ", ";os << a[i];}os<<'}';return os;}
template<class T> ostream& operator<<(ostream& os, const set<T>& a) {os << '{';int i=0;for(auto p:a){if(i>0&&i<sz(a))os << ", ";os << p;i++;}os << '}';return os;}
template<class T> ostream& operator<<(ostream& os, const set<T,greater<T> >& a) {os << '{';int i=0;for(auto p:a){if(i>0&&i<sz(a))os << ", ";os << p;i++;}os << '}';return os;}
template<class T> ostream& operator<<(ostream& os, const multiset<T>& a) {os << '{';int i=0;for(auto p:a){if(i>0&&i<sz(a))os << ", ";os << p;i++;}os << '}';return os;}
template<class T> ostream& operator<<(ostream& os, const multiset<T,greater<T> >& a) {os << '{';int i=0;for(auto p:a){if(i>0&&i<sz(a))os << ", ";os << p;i++;}os << '}';return os;}
template<class T1,class T2> ostream& operator<<(ostream& os, const map<T1,T2>& a) {os << '{';int i=0;for(auto p:a){if(i>0&&i<sz(a))os << ", ";os << p;i++;}os << '}';return os;}

const int N=5e5+5;
vector<pair<int,int> > mxpre(4*N),mxsuf(4*N);
vector<int> prearr(N),sufarr(N),cnt(N);
void initpre(int l=0,int r=N-1,int i=1){
    if(l==r){
        mxpre[i]={prearr[l],N-l};
        return;
    }
    int m=(l+r)>>1;
    initpre(l,m,2*i);
    initpre(m+1,r,2*i+1);
    mxpre[i]=max(mxpre[2*i],mxpre[2*i+1]);
}
pair<int,int> getpre(int qs,int qe,int l=0,int r=N-1,int i=1){
    if(qs>r||qe<l)
        return {INT_MIN,INT_MIN};
    if(qs<=l&&qe>=r)
        return mxpre[i];
    int m=(l+r)>>1;
    return max(getpre(qs,qe,l,m,2*i),getpre(qs,qe,m+1,r,2*i+1));
}
void initsuf(int l=0,int r=N-1,int i=1){
    if(l==r){
        mxsuf[i]={sufarr[l],l};
        return;
    }
    int m=(l+r)>>1;
    initsuf(l,m,2*i);
    initsuf(m+1,r,2*i+1);
    mxsuf[i]=max(mxsuf[2*i],mxsuf[2*i+1]);
}
pair<int,int> getsuf(int qs,int qe,int l=0,int r=N-1,int i=1){
    if(qs>r||qe<l)
        return {INT_MIN,INT_MIN};
    if(qs<=l&&qe>=r)
        return mxsuf[i];
    int m=(l+r)>>1;
    return max(getsuf(qs,qe,l,m,2*i),getsuf(qs,qe,m+1,r,2*i+1));
}
int get(int l,int r){
    if(l>r)
        return 0;
    int ans=cnt[r];
    if(l)
        ans-=cnt[l-1];
    return ans;
}
int main()
{
	//freopen("in.txt","r",stdin);
	//freopen("out.txt","w",stdout);
	int n,q;
	string s;
	cin >> n >> s >> q;
	for(int i=0;i<n;i++)
        prearr[i]=sufarr[i]=s[i]=='C'?-1:1,cnt[i]=s[i]=='T';
    for(int i=1;i<n;i++)
        prearr[i]+=prearr[i-1],cnt[i]+=cnt[i-1];
    for(int i=n-2;i>=0;i--)
        sufarr[i]+=sufarr[i+1];
    initpre();
    initsuf();
    for(int i=0;i<q;i++){
        int l,r;
        cin >> l >> r;
        l--;r--;
        auto a=getpre(l,r);
        a.s=N-a.s;
        auto b=getsuf(l,r);
        if(l)
            a.f-=prearr[l-1];
        if(r!=n-1)
            b.f-=sufarr[r+1];
        a.f=max(a.f,0);
        b.f=max(b.f,0);
        //cout << a << b << endl;
        printf("%i\n",max(0,a.f+b.f-min({a.f,b.f,get(b.s,a.s)})));
    }
    return 0;
}

• Subtask 1: 0 / 28
• Subtask 2: 0 / 54
• Subtask 3: 0 / 18