Submission #570117

#	Time	Username	Problem	Language	Result	Execution time	Memory
570117		PanTkd	Election (BOI18_election)	C++17	100 / 100	1420 ms	44364 KiB

election

//
//  main.cpp
//
//  Created by Panagiotis Chadjicostas on
//  Copyright © Panagiotis Hadjicostas. All rights reserved.
//

#include <iostream>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <fstream>
#include <iomanip>
#include <iterator>
#include <limits>
#include <list>
#include <cstring>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>
#include <unordered_map>

using namespace std;

typedef long long ll;
typedef vector<ll> vi;
typedef pair<ll,ll> ii;
#define fo(i,a,b) for(int i = a; i<=b; i++)
#define f(i,b) for(int i=0;i<b;i++)
#define F first
#define S second
#define sz size
#define ls s,m,idx<<1
#define rs m+1,e,idx<<1|1
const ll MOD=ll(1e9)+7;
const ll MAXN=2*ll(1e6);
void checker(){
    ll n=rand()%20+2;
    vi a(n,ll());
    for(ll i=0;i<n;i++){
        a[i]=rand()%20+2;
    }
    for(ll b=0;b<(1<<n);b++){
        vi on,off;
        for(ll i=0;i<n;i++){
            if(i&(1<<i)){
                on.push_back(i);
            }
            else{
                off.push_back(i);
            }
        }
    }
}
///////////////////////////////////////////////////////////////////////

struct ss{
    ll pr=0,sf=0,s=0,ans=0;
};
ss seg[2000002];
ss miden;
ss push(ss a,ss b){
    ss cc;
    cc.pr=max(a.pr,a.s+b.pr);
    cc.sf=max(b.sf,b.s+a.sf);
    cc.s=a.s+b.s;
    cc.ans = max(a.pr+b.sf, max(a.ans+b.s, b.ans+a.s));
    return cc;
}
void update(ll idx,ll s,ll e,ll u,ll val){
    if(s==e){
        seg[idx].pr = max(seg[idx].pr, val);
        seg[idx].sf = max(seg[idx].sf, val);
        seg[idx].s += val;
        seg[idx].ans = ((val == -1) ? 0 : 1);
        return;
    }
    ll m=(s+e)>>1;
    if(u<=m){
        update(idx<<1,s,m,u,val);
    }
    else{
        update(idx<<1|1,m+1,e,u,val);
    }
    seg[idx]=push(seg[idx<<1],seg[idx<<1|1]);
}
ss query(ll idx,ll s,ll e,ll qs,ll qe){
    if(s>qe||e<qs)
        return miden;
    if(s>=qs&&e<=qe){
        return seg[idx];
    }
    ll m=(s+e)>>1;
    ss q1=query(idx<<1,s,m,qs,qe);
    ss q2=query(idx<<1|1,m+1,e,qs,qe);
    return push(q1,q2);
}
void solve(){
    ll n;cin>>n;
    string s;cin>>s;
    s=' '+s;
    for(ll i=1;i<=n;i++){
        update(1, 1, n, i, ((s[i] == 'C') ? -1 : 1));
    }
    ll q;cin>>q;

    while(q--){
        ll l,r;cin>>l>>r;
        cout<<query(1,1,n,l,r).ans<<endl;
    }
}
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    ll t=1;//cin>>t;
    while (t--) {
        solve();
    }
    return 0;
}

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