Submission #621283

#	Time	Username	Problem	Language	Result	Execution time	Memory
621283		PoonYaPat	Lightning Rod (NOI18_lightningrod)	C++14	100 / 100	1850 ms	210544 KiB

Main

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

const int MX=10000005;
int n,a[MX],b[MX];
stack<int> st;

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin>>n;
    for (int i=1; i<=n; ++i) {
        int x,y;
        cin>>x>>y;
        a[i]=x-y;
        b[i]=x+y;
    }
    st.push(1);
    for (int i=2; i<=n; ++i) {
        int k=st.top();
        if (b[i]>b[st.top()]) {
            while (!st.empty() && a[i]<=a[st.top()]) st.pop();
            st.push(i);
        }
    }
    cout<<st.size();
}

Compilation message (stderr)

lightningrod.cpp: In function 'int main()':
lightningrod.cpp:19:13: warning: unused variable 'k' [-Wunused-variable]
   19 |         int k=st.top();
      |             ^

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