Submission #219586

#	Time	Username	Problem	Language	Result	Execution time	Memory
219586		GioChkhaidze	Lightning Rod (NOI18_lightningrod)	C++14	66 / 100	2080 ms	171132 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;
main () {
	scanf("%d",&n);
	for (int i=1; i<=n; i++) {
		scanf("%d%d",&x[i],&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:7:7: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main () {
       ^
lightningrod.cpp: In function 'int main()':
lightningrod.cpp:8:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
lightningrod.cpp:10:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&x[i],&y[i]);
   ~~~~~^~~~~~~~~~~~~~~~~~~~

• 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