Submission #544628

#	Time	Username	Problem	Language	Result	Execution time	Memory
544628		AbdelmagedNour	Lightning Rod (NOI18_lightningrod)	C++17	40 / 100	1681 ms	262144 KiB

Main

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
const int N=10000005;
int n,x[N],y[N],a[N],b[N],nxta[N],nxtb[N];
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>x[i]>>y[i];
        a[i]=y[i]-x[i];
        b[i]=y[i]+x[i];
    }
    stack<int>st;
    for(int i=n-1;i>=0;i--){
        while(!st.empty()&&a[st.top()]<a[i])st.pop();
        nxta[i]=(st.empty()?-1:st.top());
        st.push(i);
    }
    st=stack<int>();
    for(int i=n-1;i>=0;i--){
        while(!st.empty()&&b[st.top()]<b[i])st.pop();
        nxtb[i]=(st.empty()?n:st.top());
        st.push(i);
    }
    int res=0;
    int pos=0;
    while(pos<n){
        res++;
        while(nxta[pos]!=-1)pos=nxta[pos];
        pos=nxtb[pos];
    }
    cout<<res;
    return 0;
}

• Subtask 1: 0 / 4
• Subtask 2: 7 / 7
• Subtask 3: 12 / 12
• Subtask 4: 21 / 21
• Subtask 5: 0 / 26
• Subtask 6: 0 / 10
• Subtask 7: 0 / 20