Submission #313304

#	Time	Username	Problem	Language	Result	Execution time	Memory
313304		kaplanbar	Lightning Rod (NOI18_lightningrod)	C++11	66 / 100	2093 ms	75728 KiB

Main

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
constexpr int N = 1e7+1;
int n;
bool v[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++) {
      scanf("%d %d", &a[i].first, &a[i].second);
      //cin >> a[i].first >> a[i].second;
    }
    int mx = -2000000000;
    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 = -2000000000;
    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 += v[i];
    //cout << n-ans;
    printf("%d",n-ans);
    return 0;
}

Compilation message (stderr)

lightningrod.cpp: In function 'int main()':
lightningrod.cpp:13:12: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   13 |       scanf("%d %d", &a[i].first, &a[i].second);
      |       ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• 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