# | 제출 시각 | 아이디 | 문제 | 언어 | 결과 | 실행 시간 | 메모리 |
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219594 | 2020-04-05T16:35:24 Z | GioChkhaidze | Lightning Rod (NOI18_lightningrod) | C++14 | 0 ms | 0 KB |
#include <bits/stdc++.h> using namespace std; const int N=1e7+7; bool f[N]; register int c; int n,x,y,X[N],Y[N],st[N],sts; int getn() { char ch = getchar_unlocked(); int ans = 0; while(!isdigit(ch)) { ch = getchar_unlocked(); } while(isdigit(ch)) { ans = ans * 10 + ch - '0'; ch = getchar_unlocked(); } return ans; } main () { n=getn(); for (int i=1; i<=n; i++) { x=getn(); y=getn(); X[i]=x-y; Y[i]=x+y; } for (int i=1; i<=n; i++) { if (sts) { while (sts && X[st[sts]]>=X[i]) { f[st[sts]]=1; --sts; } } st[++sts]=i; } sts=0; for (int i=n; i>=1; i--) { if (f[i]) continue; if (sts) { while (sts && Y[st[sts]]<=Y[i]) { --sts; } } st[++sts]=i; } cout<<sts; }