Submission #198137

#	Time	Username	Problem	Language	Result	Execution time	Memory
198137		popovicirobert	Lightning Rod (NOI18_lightningrod)	C++14	66 / 100	2070 ms	242096 KiB

Main

#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
#define uint unsigned int


using namespace std;

const int MAXN = (int) 1e7 + 5;

int x[MAXN + 1], y[MAXN + 1];
int stk[MAXN + 1], sp[MAXN + 1];

int main() {
#ifdef HOME
    ifstream cin("A.in");
    ofstream cout("A.out");
#endif
    int i, n;
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    cin >> n;

    for(i = 1; i <= n; i++) {
        cin >> x[i] >> y[i];
    }

    stk[0] = -1;

    int sz = 0;
    for(i = 1; i <= n; i++) {
        while(sz > 0 && x[i] - x[stk[sz]] <= y[i] - y[stk[sz]]) {
            sz--;
        }
        sp[stk[sz] + 1]++;
        stk[++sz] = i;
    }

    sz = 0, stk[0] = n + 1;
    for(i = n; i >= 1; i--) {
        while(sz > 0 && x[stk[sz]] - x[i] <= y[i] - y[stk[sz]]) {
            sz--;
        }
        sp[stk[sz]]--;
        stk[++sz] = i;
    }

    int ans = 0;
    for(i = 1; i <= n; i++) {
        sp[i] += sp[i - 1];
        ans += (sp[i] == 1);
    }

    cout << ans;

    return 0;
}

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