Submission #961463

#	Time	Username	Problem	Language	Result	Execution time	Memory
961463		vjudge1	Lightning Rod (NOI18_lightningrod)	C++17	100 / 100	1387 ms	186548 KiB

Main

#include <bits/stdc++.h>
 
#pragma optimize("Ofast")
#pragma target("avx2")
 
using namespace std;
 
#define ll long long
#define ld long double
#define pb push_back
#define pf push_front
#define pii pair<int,int>
#define all(v) v.begin(),v.end()
#define F first
#define S second
#define mem(a,i) memset(a,i,sizeof(a))
#define sz(s) (int)s.size()
#define y1 yy
#define ppb pop_back
#define lb lower_bound
#define ub upper_bound
#define gcd(a,b) __gcd(a,b)
#define in insert
// #define int ll
 
const int MAX=5e5+5;
const int B=90;
const int N=105;
const int block=400;
const int maxB=MAX/B+10;
const ll inf=2e18;  
const int mod=998244353;
const int mod1=1e9+9;
const ld eps=1e-9;
 
int dx[8]={1,0,-1,0,1,-1,-1,1};
int dy[8]={0,1,0,-1,1,-1,1,-1};
 
int binpow(int a,int n){
  if(!n)return 1;
  if(n%2==1)return a*binpow(a,n-1)%mod;
  int k=binpow(a,n/2);
  return k*k%mod;
}

int n;
vector<pii> v;

void solve(){
  cin>>n;
  ll mx=-inf;
  ll px=-inf,py=-inf;
  for(int i=1;i<=n;i++){
    int x,y;
    cin>>x>>y;
    if(x+y>mx){
      if(!v.empty()&&v[sz(v)-1].F==x){
        v[sz(v)-1].S=max(v[sz(v)-1].S,-x+y);
      }
      else v.pb({x,-x+y});
      mx=x+y;
    }
    px=x,py=y;
  }
  int ans=0;
  mx=inf;
  for(int i=sz(v)-1;i>=0;i--){
    if(-v[i].S<mx){
      mx=-v[i].S;
      ans++;
    }
  }
  cout<<ans;
}

signed main(){
  //  freopen("help.in","r",stdin);
  //  freopen("help.out","w",stdout);
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  // prec();
  int t=1;
  // cin>>t;
  while(t--)solve();
}

Compilation message (stderr)

lightningrod.cpp:3: warning: ignoring '#pragma optimize ' [-Wunknown-pragmas]
    3 | #pragma optimize("Ofast")
      | 
lightningrod.cpp:4: warning: ignoring '#pragma target ' [-Wunknown-pragmas]
    4 | #pragma target("avx2")
      | 
lightningrod.cpp: In function 'void solve()':
lightningrod.cpp:52:6: warning: variable 'px' set but not used [-Wunused-but-set-variable]
   52 |   ll px=-inf,py=-inf;
      |      ^~
lightningrod.cpp:52:14: warning: variable 'py' set but not used [-Wunused-but-set-variable]
   52 |   ll px=-inf,py=-inf;
      |              ^~

• 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