Submission #255621

#	Time	Username	Problem	Language	Result	Execution time	Memory
255621		tleontest1	Stove (JOI18_stove)	C++17	100 / 100	77 ms	8788 KiB

stove

#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
#pragma GCC optimize ("unroll-loops")
#pragma GCC target ("avx2")

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long lo;
typedef pair< lo,lo > PII;
typedef pair< lo,PII > PIII;
 
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define fio() ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL)
#define FOR for(int i=1;i<=n;i++)
#define mid ((start+end)/2)
#define ort ((bas+son)/2)
 
const lo MAX = -1000000000000000000;
const lo MIN = 1000000000000000000;
const lo inf = 1000000000;
const lo KOK = 100000;
const lo LOG = 30;
const lo li = 500005;
const lo mod = 1000000007;
 
int n,m,b[li],a[li],k,flag,t,fa[li],vis[li];
int cev;
multiset <PIII> st;
string s;
vector<int> v;
 
inline int dsu(int x){
	if(x==fa[x])return x;
	return fa[x]=dsu(fa[x]);
}
 
int main(void){
	scanf("%d %d",&n,&m);
	FOR fa[i]=i;
	int at=n-m;
	FOR{
		scanf("%d",&a[i]);
		if(i>1)st.insert(mp(a[i]-a[i-1],mp(i,i-1)));
	}
	while(at>0){
		at--;
		PIII p;
		auto it=st.begin();
		st.erase(it);
		p=*it;
		fa[dsu(p.se.fi)]=dsu(p.se.se);
		cev+=p.fi;
		//~ cout<<cev<<endl;
	}
	FOR{
		if(vis[dsu(i)]==0)cev++;
		vis[dsu(i)]=1;
	}
	printf("%d\n",cev);
	return 0;
}

Compilation message (stderr)

stove.cpp: In function 'int main()':
stove.cpp:43:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d",&n,&m);
  ~~~~~^~~~~~~~~~~~~~~
stove.cpp:47:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&a[i]);
   ~~~~~^~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 50 / 50