Submission #219587

#	Time	Username	Problem	Language	Result	Execution time	Memory
219587		GioChkhaidze	Lightning Rod (NOI18_lightningrod)	C++14	80 / 100	2089 ms	228236 KiB

Main

#include <bits/stdc++.h>
using namespace std;
const int N=1e7+7;
bool f[N];
int n,x[N],y[N];
stack < int > st;

void fastscan(int &number)  { 
  register int c; 
  number = 0; 
  c = getchar(); 
  for (; (c>47 && c<58); c=getchar()) 
      number = number *10 + c - 48; 
} 

main () {
	fastscan(n);
	for (int i=1; i<=n; i++) {
		fastscan(x[i]);
		fastscan(y[i]);
	}
	
	int ans=n;
	for (int i=1; i<=n; i++) {
		if (st.size()) {
			while (st.size() && x[st.top()]-y[st.top()]>=x[i]-y[i]) {
				f[st.top()]=1;
				--ans;
				st.pop();
			}
		}
		st.push(i);
	}
	
	while (st.size()) st.pop();
	
	for (int i=n; i>=1; i--) {
		if (f[i]) continue;
		if (st.size()) {
			while (st.size() && x[st.top()]+y[st.top()]<=x[i]+y[i]) {
				f[st.top()]=1;
				--ans;
				st.pop();
			}
		}
		st.push(i);
	}
	
	printf("%d\n",ans);
}

Compilation message (stderr)

lightningrod.cpp:16:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main () {
       ^

• 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