Submission #712098

#	Time	Username	Problem	Language	Result	Execution time	Memory
712098		Pherokung	Lightning Rod (NOI18_lightningrod)	C++14	80 / 100	2062 ms	153816 KiB

Main

#include<bits/stdc++.h>
using namespace std;
#define MAXN 10000005
#define F first
#define S second
int n,x[MAXN],y[MAXN],rod[MAXN],ans=0;
deque<int> dq;

int main(){
	scanf("%d",&n);
	ans = n;
	for(int i=1;i<=n;i++){
		scanf("%d%d",&x[i],&y[i]);
		rod[i] = 1;
		
		while(!dq.empty()){
			int p = dq.front();
			if(y[i] - x[i] >= y[p] - x[p]){
				if(rod[p] == 1){
					rod[p] = 0;
					ans--;
				}
				dq.pop_front();
			}
			else break;
		}
		dq.push_front(i);
	}
	
	while(!dq.empty()) dq.pop_front();
	
	for(int i=n;i>=1;i--){
		while(!dq.empty()){
			int p = dq.front();
			if(y[i] + x[i] >= y[p] + x[p]){
				if(rod[p] == 1){
					rod[p] = 0;
					ans--;
				}
				dq.pop_front();
			}
			else break;
		}
		dq.push_front(i);
	}
	
	printf("%d",ans);
}

Compilation message (stderr)

lightningrod.cpp: In function 'int main()':
lightningrod.cpp:10:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |  scanf("%d",&n);
      |  ~~~~~^~~~~~~~~
lightningrod.cpp:13:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   13 |   scanf("%d%d",&x[i],&y[i]);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~

• 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