Submission #347387

#	Time	Username	Problem	Language	Result	Execution time	Memory
347387		Sho10	Election (BOI18_election)	C++14	100 / 100	725 ms	48640 KiB

election

#include <bits/stdc++.h> //Andrei Alexandru a.k.a Sho10
#define ll long long 
#define double long double
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#define aint(a) (a).begin(), (a).end()
#define f first
#define s second
#define pb push_back
#define mp make_pair
#define pi pair
#define rc(s) return cout<<s,0
#define endl '\n'
#define mod 1000000007
#define PI 3.14159265359
#define MAXN 100005
#define INF 1000000005
#define LINF 1000000000000000005ll
#define CODE_START  ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
using namespace std;
ll n,q,a[500005];
string s;
struct nodee{
	ll pref;
	ll suf;
	ll sum;
	ll res;
};
nodee tree[10000005];
nodee con(nodee x,nodee y){
nodee ans;
ans.pref=max(x.pref,x.sum+y.pref);
ans.suf=max(y.suf,y.sum+x.suf);
ans.sum=x.sum+y.sum;
ans.res=max(x.pref+y.suf,max(x.sum+y.res,y.sum+x.res));
return ans;
}
void build(ll node,ll l,ll r){
if(l==r){
	tree[node].pref=max(0ll,a[l]);
	tree[node].suf=max(0ll,a[l]);
	tree[node].sum=a[l];
	tree[node].res=max(0ll,a[l]);
	return;
}
ll mid=(l+r)/2;
build(2*node,l,mid);
build(2*node+1,mid+1,r);
tree[node]=con(tree[node*2],tree[node*2+1]);
}
nodee query(ll node,ll l,ll r,ll st,ll dr){
	if(l>dr){
		return {};
	}
	if(r<st){
		return {};
	}
	if(st<=l&&r<=dr){
		return tree[node];
	}
	ll mid=(l+r)/2;
	return con(query(2*node,l,mid,st,dr),query(2*node+1,mid+1,r,st,dr));
}
int32_t main(){
CODE_START;
cin>>n;
cin>>s;
for(ll i=0;i<s.size();i++)
{
	ll s1=0;
	if(s[i]=='C'){
		s1=-1;
	}else s1=+1;
	a[i+1]=s1;
}
build(1,1,n);
cin>>q;
while(q--){
	ll l,r;
	cin>>l>>r;
	cout<<query(1,1,n,l,r).res<<endl;
}
}

Compilation message (stderr)

election.cpp: In function 'int32_t main()':
election.cpp:68:13: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 | for(ll i=0;i<s.size();i++)
      |            ~^~~~~~~~~

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