Submission #1232892

#	Time	Username	Problem	Language	Result	Execution time	Memory
1232892		almaharbas4	Election (BOI18_election)	C++20	0 / 100	3 ms	320 KiB

election

#include<bits/stdc++.h>
using namespace std;
struct Node
{
    int suf;
    int pref;
    int sum;
    int ans;
    //Node() : suf(0),pref(0),sum(0),ans(0){}
};
vector<Node> seg;
vector<int> val;
Node merge(Node n,Node m)
{
    Node parent;
    parent.sum=n.sum+m.sum;
    parent.pref=max(n.pref,n.sum+m.pref);
    parent.suf=max(m.suf,m.sum+n.suf);
    parent.ans=max({n.ans+m.suf,m.ans+n.pref,n.pref+m.suf});
    return parent;
}
void update(int idx,int l,int r)
{
    if(l==r)
    {
        if(val[l]==1) seg[idx]={1,1,1,1};
        else seg[idx]={0,0,-1,0}; 
        return;
    }
    int mid=(l+r)/2;
    update(2*idx,l,mid); 
    update(2*idx+1,mid+1,r);
    seg[idx]=merge(seg[idx*2],seg[idx*2+1]);
}
Node upit(int idx,int start,int end,int l,int r)
{
    if(r<start||l>end) return {0,0,0,0};
    if(l<=start&&r>=end)
    {
        return seg[idx];
    }
    int mid=(start+end)/2;
    Node n=upit(idx*2,start,mid,l,r);
    Node m=upit(idx*2+1,mid+1,end,l,r);
    return merge(n,m);
}
int main()
{
    int len;
    cin>>len;
    seg.resize(4*len);
    val.resize(len);
    string s;
    cin>>s;
    for(int i=0;i<len;i++) val[i]=((s[i]=='T')?1:-1);
    update(1,0,len-1);
    int q;
    cin>>q;
    while(q--)
    {
        int l,r;
        cin>>l>>r;
        l--;r--;
        Node n=upit(1,0,len-1,l,r);
        cout<<n.ans<<'\n';
    }

    return 0;
}

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