Submission #1196808

#	Time	Username	Problem	Language	Result	Execution time	Memory
1196808		loom	Lightning Rod (NOI18_lightningrod)	C++20	100 / 100	493 ms	235204 KiB

Main

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

inline int readInt() {
   int x = 0;
   char ch = getchar();
   while(ch < '0' || ch > '9') ch = getchar_unlocked();
   while(ch >= '0' && ch <= '9'){
      x = (x << 3) + (x << 1) + ch - '0';
      ch = getchar_unlocked();
	}
   return x;
}

signed main(){
	int n = readInt();
	vector<pair<int,int>> a(n);
	for(int i = 0; i < n; i++) {
		a[i].first = readInt();
		a[i].second = readInt();
	}

   int ans = n;
   int mx = -1;
   vector<int> tf(n, 0);
   for(int i=0; i<n; i++){
      auto [x, y] = a[i];

      if(x+y <= mx) ans--, tf[i] = 1;
      else mx = x+y;
   }
   int mn = 1e18;
   for(int i=n-1; i>=0; i--){
      if(tf[i]) continue;
      auto [x, y] = a[i];

      if(x-y >= mn) ans--;
      else mn = x-y;
   }

   cout<<ans;
	return 0;
}

• 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