Submission #496830

#	Time	Username	Problem	Language	Result	Execution time	Memory
496830		SirCovidThe19th	Lightning Rod (NOI18_lightningrod)	C++17	100 / 100	1918 ms	262144 KiB

Main

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

#define FOR(i, x, y) for (int i = x; i < y; i++)
#define pii pair<int, int>
#define f first
#define s second

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); 
    int n; cin >> n; 
    bool covered[n] = {}; pii A[n]; stack<pii> S;

    FOR(i, 0, n){
        cin >> A[i].f >> A[i].s;
        while (!S.empty() and S.top().f >= A[i].f - A[i].s){
            covered[S.top().s] = 1;
            S.pop();
        }
        S.push({A[i].f - A[i].s, i});
    }
    S = stack<pii>();
    for (int i = n - 1; ~i; i--) if (!covered[i]){
        while (!S.empty() and S.top().f <= A[i].f + A[i].s){
            covered[S.top().s] = 1;
            S.pop();
        }
        S.push({A[i].f + A[i].s, i});
    }
    cout<<n - accumulate(covered, covered + n, 0)<<endl;
}

• 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