Submission #1089816

#	Time	Username	Problem	Language	Result	Execution time	Memory
1089816		lucri	Election (BOI18_election)	C++17	100 / 100	345 ms	45908 KiB

election

#include <bits/stdc++.h>
using namespace std;
char a[500010];
bool e[500010];
int n,q,x,y,ans[500010];
vector<pair<int,int>>qu[500010];
struct arboreintervale{int sum,minp;}aint[2000010],zero;
arboreintervale join(arboreintervale a,arboreintervale b)
{
    arboreintervale c;
    c.sum=a.sum+b.sum;
    c.minp=min(a.minp,a.sum+b.minp);
    return c;
}
stack<int>s;
void update(int poz,int b,int e,int pozu,int val)
{
    if(b>pozu||e<pozu)
        return;
    if(b==e)
    {
        aint[poz].sum=val;
        aint[poz].minp=min(0,val);
        return;
    }
    update(poz*2,b,(b+e)/2,pozu,val);
    update(poz*2+1,(b+e)/2+1,e,pozu,val);
    aint[poz]=join(aint[poz*2],aint[poz*2+1]);
}
arboreintervale interval(int poz,int b,int e,int lim)
{
    if(e<lim)
        return zero;
    if(b>=lim)
        return aint[poz];
    return join(interval(poz*2,b,(b+e)/2,lim),interval(poz*2+1,(b+e)/2+1,e,lim));
}
int aib[500010];
int suma(int poz)
{
    int ans=0;
    for(;poz>=1;poz-=(poz&(-poz)))
        ans+=aib[poz];
    return ans;
}
void aduna(int poz,int val)
{
    for(;poz<=n;poz+=(poz&(-poz)))
        aib[poz]+=val;
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin>>n>>a+1>>q;
    for(int i=1;i<=q;++i)
    {
        cin>>x>>y;
        qu[y].push_back({x,i});
    }
    for(int i=1;i<=n;++i)
    {
        if(a[i]=='T')
        {
            s.push(i);
            aduna(i,1);
        }
        else
        {
            update(1,1,n,i,1);
            if(!s.empty())
            {
                update(1,1,n,s.top(),-1);
                aduna(s.top(),-1);
                s.pop();
            }
        }
        for(auto x:qu[i])
        {
            arboreintervale arb=interval(1,1,n,x.first);
            ans[x.second]=s.size()-arb.minp-suma(x.first-1);
        }
    }
    for(int i=1;i<=q;++i)
        cout<<ans[i]<<'\n';
    return 0;
}

Compilation message (stderr)

election.cpp: In function 'int main()':
election.cpp:56:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   56 |     cin>>n>>a+1>>q;
      |             ~^~

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