Submission #108018

#	Time	Username	Problem	Language	Result	Execution time	Memory
108018		brcode	Election (BOI18_election)	C++14	82 / 100	276 ms	13388 KiB

election

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
const int MAXN =1e5+5;
struct node{
    int sum,suffsum;
    node(int sum = 0,int suffsum = 0){
        this->sum = sum;
        this->suffsum = suffsum;
    }
    node join(node &other){
        return node(sum+other.sum,min(other.suffsum,other.sum+suffsum));
    }
};
node a[4*MAXN + 5];
void update(int curr,int l,int r,int pos,int val){
    
    if(pos>r||pos<l){
        return;
    }
   // cout<<pos<<" "<<l<<" "<<r<<endl;
    if(l == r){
        a[curr].sum+=val;
        a[curr].suffsum+=val;
        return;
    }
    int mid = (l+r)/2;
    update(2*curr,l,mid,pos,val);
    update(2*curr+1,mid+1,r,pos,val);
    a[curr] = a[2*curr].join(a[2*curr+1]);
}
node query(int curr,int l, int r,int tl,int tr){
    if(tl>r||tr<l){
        node temp;
        temp.sum = 0;
        temp.suffsum = 0;
        return temp;
    }
    if(tl<=l && r<=tr){
        return a[curr];
    }
    int mid = (l+r)/2;
    node a = query(2*curr,l,mid,tl,tr);
    node b = query(2*curr+1,mid+1,r,tl,tr);
    return a.join(b);
}
int n,q;
int rem[MAXN];
int len;
int holdans[MAXN];
vector<pair<int,int>> queries[MAXN];
int main(){

    cin>>n;
    string s;
    cin>>s;
 
    cin>>q;
    
    s = '#' + s;
    for(int i=1;i<=q;i++){
        int l,r;
        cin>>l>>r;
        queries[l].push_back(make_pair(r,i));
    }
    for(int i=n;i>=1;i--){
        if(s[i] == 'T'){
            rem[len++] = i;
            
        }else{
            update(1,1,n,i,1);
           //cout<<query(1,1,n,i,n).suffsum<<endl;
            if(len){
                update(1,1,n,rem[len-1],-1);
                
                //cout<<rem[len-1]<<endl;
                len--;
            }
        }
        for(auto it:queries[i]){
            //cout<<len<<" "<<it.first<<endl;
            int l=0;
            int r = len-1;
            int ans = -1;
            while(l<=r){
                int mid = (l+r)/2;
               // cout<<rem[mid]<<endl;
                if(rem[mid]>it.first){
                    ans = mid;
                    //cout<<123<<" "<<mid<<" "<<rem[mid]<<" "<<it.first<<endl;
                    l=mid+1;
                }else{
                   
                    //ans = mid;
                    r=mid-1;
                }
            }
            //cout<<len<<" "<<len-ans-1<<endl;
            //cout<<len<<" "<<ans+1<<endl;
          //  cout<<-1*query(1,1,n,i,it.first).suffsum<<endl;
         //cout<<ans+1<<endl;
            holdans[it.second] = max(0,-1*query(1,1,n,i,it.first).suffsum) + len-ans-1;
            
        }
        
    }
    for(int i=1;i<=q;i++){
        cout<<holdans[i]<<endl;
    }
}

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