Submission #759365

#	Time	Username	Problem	Language	Result	Execution time	Memory
759365		Bula	Election (BOI18_election)	C++17	0 / 100	15 ms	20020 KiB

election

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

#define ll long long
const ll mod=1e9+7,N=5e5+1;
vector<int> pref(N),suf(N+1),t(4*N),t1(4*N);



int getans(int v,int tl,int tr,int l,int r){
	if(l>r) return 0;
	if(l==tl && r==tr){
		return t[v];
	}
	int tm=(tl+tr)/2;
	return max(getans(v*2,tl,tm,l,min(r,tm)),getans(v*2+1,tm+1,tr,max(l,tm+1),r));
}

void build(int v,int tl,int tr){
	if(tl==tr){
		t[v]=pref[tl];
	}else{
		int tm=(tl+tr)/2;
		build(v*2,tl,tm);
		build(v*2+1,tm+1,tr);
		t[v]=max(t[v*2],t[v*2+1]);
	}
}

int getans1(int v,int tl,int tr,int l,int r){
	if(l>r) return 0;
	if(l==tl && r==tr){
		return t1[v];
	}
	int tm=(tl+tr)/2;
	return max(getans1(v*2,tl,tm,l,min(r,tm)),getans1(v*2+1,tm+1,tr,max(l,tm+1),r));
}

void build1(int v,int tl,int tr){
	if(tl==tr){
		t1[v]=suf[tl];
	}else{
		int tm=(tl+tr)/2;
		build1(v*2,tl,tm);
		build1(v*2+1,tm+1,tr);
		t1[v]=max(t1[v*2],t1[v*2+1]);
	}
}

int main(){
    ios::sync_with_stdio(0);
    cin.tie(0),cout.tie(0);
	int n;
	cin>>n;
	string s;
	cin>>s;
	vector<int> v(n+1);
	for(int i=1;i<=n;i++){
		if(s[i-1]=='T') v[i]=1;
		else v[i]=-1;
	}
	
	for(int i=1;i<=n;i++){
		pref[i]=pref[i-1]+v[i];
	}	
	for(int i=n;i>=1;i--){
		suf[i]=suf[i+1]+v[i];
	}
	build(1,1,n);
	build1(1,1,n);
	
	int q;
	cin>>q;
	for(int i=1;i<=q;i++){
		int l,r;
		cin>>l>>r;
		cout<<max(getans(1,1,n,l,r)-pref[l-1],getans1(1,1,n,l,r)-suf[r+1])<<endl;
	}
}

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