Submission #313299

#	Time	Username	Problem	Language	Result	Execution time	Memory
313299		kaplanbar	Lightning Rod (NOI18_lightningrod)	C++14	80 / 100	2091 ms	85040 KiB

Main

#include <bits/stdc++.h>
using namespace std;
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
using ll = long long;
constexpr int N = 1e7+1;
int n;
pair<int,int> a[N];
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cin >> n;
    for(int i = 0; i < n; i++) {
      cin >> a[i].first >> a[i].second;
    } 
    vector<bool> v(n, 0);
    int mx = -2e9;
    for(int i = 0; i < n; i++) {
      int val = a[i].first + a[i].second;
      if(mx >= val) {
        v[i] = 1;
      }
      else {
        mx = val;
      }
    }
    mx = -2e9;
    for(int i = n - 1; i >= 0; i--) {
      int val = a[i].second - a[i].first;
      if(mx >= val) {
        v[i] = 1;
      }
      else {
        mx = val;
      }
    }
    int ans = 0;
    for(int i = 0; i < n; i++) ans += 1^v[i];
    cout << ans;
    return 0;
}

Compilation message (stderr)

lightningrod.cpp:4: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
    4 | #pragma GCC optimization ("O3")
      | 
lightningrod.cpp:5: warning: ignoring #pragma GCC optimization [-Wunknown-pragmas]
    5 | #pragma GCC optimization ("unroll-loops")
      |

• 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: 0 / 20