Submission #949417

#	Time	Username	Problem	Language	Result	Execution time	Memory
949417		vjudge1	Sirni (COCI17_sirni)	C++17	140 / 140	4296 ms	628764 KiB

sirni

#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>
 
#define ff first
#define ss second
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define rnd(l, r) uniform_int_distribution<int>(l, r)(rng)
#define int long long

using namespace std;

void fp(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);} 
int pow(int a,int b,int m){int ans=1;while(b){if(b&1){ans=(ans*a)%m;}b>>=1;a=(a*a)%m;}return ans;}
int binpow(int a,int b){int ans=1;while(b){if(b&1){ans=(ans*a);}b>>=1;a=(a*a);}return ans;}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
 
const int N = 1e7 + 2;

int32_t p[N];
bool have[N];
int32_t par[N],sz[N];

int find(int a){
    if(par[a] == a)
        return a;
    return par[a] = find(par[a]);
}
void connect(int a, int b){
    a = find(a);
    b = find(b);
    if(a==b)
		return;
	if(sz[a] < sz[b])
		swap(a,b);
 
	par[b] = a;
	sz[a] += sz[b];
}
vector <pair <int32_t, int32_t> > g[N];
main(){
	iostream::sync_with_stdio(false);	
    cin.tie(nullptr);
    cout.tie(nullptr);
    //cout << "---" << endl;
	int n;
	cin >> n;
	set <int32_t> st;
	for(int i = 1; i <= n; i++){
		cin >> p[i];
		have[p[i]] = 1;
		st.insert(p[i]);
	}
	
	for(int32_t i = 1; i < N; i++){
		if(!have[i])continue;
		while(!st.empty() && *st.begin() <= i)
			st.erase(st.begin());
		if(st.empty())break;
		sz[i] = 1;
		par[i] = i;
		for(int32_t j = i; j < N; j += i){
			if(have[j] == 1 && i != j){
				g[0].pb({j, i});
			}
			auto it = st.upper_bound(j);	
			if(it == st.end())break;
			j = *it;	
			j = j - (j % i);
			g[*it - j].pb({*it, i});
		}
	}
	long long ans = 0;
	for(int i = 0; i < N;i++){
		for(auto x : g[i]){
			if(find(x.ff) != find(x.ss)){
				connect(x.ff, x.ss);
				ans += i;
			}
		}
	}
	cout << ans << endl;
}	
/*
 * Before implementing the problem:
	
	Do I understand the problem correctly?
	Which places are tricky? What do I need to remember to implement them correctly?
	Which place is the heaviest by implementation? Can I do it simpler?
	Which place is the slowest? Where do I need to be careful about constant factors and where I can choose slower but simpler implementation?
	----------------------------------
	If not AC:
 
	Did you remember to do everything to handle the tricky places you thought about before?
	Is the solution correct?
	Do I understand the problem correctly?
	----------------------------------
	If you have a test on which the solution gives wrong answer:
 
	Is the solution doing what it was supposed to do?
	Is the problem in the code or in the idea?
*/

Compilation message (stderr)

sirni.cpp:43:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   43 | main(){
      | ^~~~
sirni.cpp: In function 'void fp(std::string)':
sirni.cpp:15:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 | void fp(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
sirni.cpp:15:70: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 | void fp(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                                                               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 14 / 14
• Subtask 2: 14 / 14
• Subtask 3: 14 / 14
• Subtask 4: 14 / 14
• Subtask 5: 14 / 14
• Subtask 6: 14 / 14
• Subtask 7: 14 / 14
• Subtask 8: 14 / 14
• Subtask 9: 14 / 14
• Subtask 10: 14 / 14