Submission #743087

#	Time	Username	Problem	Language	Result	Execution time	Memory
743087		Joo	Lightning Rod (NOI18_lightningrod)	C++17	100 / 100	397 ms	79684 KiB

Main

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

bool isContain(pair<int, int> &a, pair<int, int> &b)
{
    return (abs(a.first - b.first) <= a.second - b.second);
}

inline void read(int &x)
{
    x = 0;
    char ch = getchar_unlocked();
    while (ch & 16)
    {
        x = (x << 3) + (x << 1) + (ch & 15);
        ch = getchar_unlocked();
    }
}

int main()
{
    cin.tie(0)->sync_with_stdio(0);
    int n;
    read(n);
    stack<pair<int, int>> st;
    for (int i = 1; i <= n; i++)
    {
        pair<int, int> tmp;
        int x, y;
        read(x), read(y);
        tmp = {x, y};
        while (!st.empty() and isContain(tmp, st.top()))
            st.pop();
        if (st.empty() or !isContain(st.top(), tmp))
            st.push(tmp);
    }
    cout << st.size() << "\n";
}

• 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