Submission #251625

#	Time	Username	Problem	Language	Result	Execution time	Memory
251625		jamielim	Candies (JOI18_candies)	C++14	100 / 100	648 ms	27384 KiB

candies

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int,int> ii;
typedef pair<ll,ll> pll;
typedef long double ld;
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define ALL(x) x.begin(),x.end()
#define SZ(x) (int)x.size()
const int INF=2012345678;
const ll LLINF=4012345678012345678LL;
const ll MOD=1000000007; //998244353; //
const ld PI=3.1415926535898;
const ld EPS=1e-9;
ll gcd(ll a,ll b){if(a<b)swap(a,b);if(b==0)return a;return gcd(b,a%b);}
inline ll lcm(ll a,ll b){return a/gcd(a,b)*b;}
inline ll expo(ll b,ll p,ll m){ll res=1; while(p){if(p&1)res=(res*b)%m; b=(b*b)%m; p>>=1;} return res;}
inline ll modinv(ll a,ll m){return expo(a,m-2,m);}

int main(){
	int n;
	scanf("%d",&n);
	ll arr[n];
	for(int i=0;i<n;i++)scanf("%lld",&arr[i]);
	set<pair<ll,int> > s;
	set<int> idx;
	for(int i=0;i<n;i++){
		s.insert(mp(arr[i],i));
		idx.insert(i);
	}
	ll sum=0;
	for(int i=0;i<(n+1)/2;i++){
		auto it=(--s.end());
		sum+=(it->fi);printf("%lld\n",sum);
		int x=(it->se);idx.erase(x);s.erase(it);
		auto l=idx.lower_bound(x),r=idx.lower_bound(x+1);
		arr[x]=-arr[x];
		bool add=1;
		if(l==idx.begin())add=0;
		else{
			--l;
			arr[x]+=arr[*l];
			s.erase(mp(arr[*l],*l));
			idx.erase(l);
		}
		if(r==idx.end())add=0;
		else{
			arr[x]+=arr[*r];
			s.erase(mp(arr[*r],*r));
			idx.erase(r);
		}
		if(add){s.insert(mp(arr[x],x));idx.insert(x);}
	}
}

Compilation message (stderr)

candies.cpp: In function 'int main()':
candies.cpp:26:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
candies.cpp:28:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i=0;i<n;i++)scanf("%lld",&arr[i]);
                      ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 92 / 92