Submission #341895

# Submission time Handle Problem Language Result Execution time Memory
341895 2020-12-31T11:56:07 Z AmineWeslati Hotter Colder (IOI10_hottercolder) C++14
25 / 100
872 ms 8300 KB
//Never stop trying
/*#pragma GCC target ("avx2")
#pragma GCC optimize ("Ofast")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")*/
#include "bits/stdc++.h"
using namespace std;
#define boost ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0)

typedef long long ll;
typedef string str;
typedef double db;
typedef long double ld;
typedef pair<int, int> pi;
#define fi first
#define se second
typedef vector<int> vi;
typedef vector<pi> vpi;
typedef vector<str> vs;
typedef vector<ld> vd;
#define pb push_back
#define eb emplace_back
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define endl "\n"

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)

const int MOD = 1e9 + 7; //998244353
const ll INF = 1e18;
const int MX = 2e5 + 10;
const int nx[4] = {0, 0, 1, -1}, ny[4] = {1, -1, 0, 0}; //right left down up

template<class T> using V = vector<T>;
template<class T> bool ckmin(T& a, const T& b) { return a > b ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }

ll cdiv(ll a, ll b) { return a / b + ((a ^ b) > 0 && a % b); } // divide a by b rounded up
//constexpr int log2(int x) { return 31 - __builtin_clz(x); } // floor(log2(x))

mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
//mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());

ll random(ll a, ll b){
    return a + rng() % (b - a + 1);
}

#ifndef LOCAL  
#define cerr if(false) cerr
#endif
#define dbg(x) cerr << #x << " : " << x << endl; 
#define dbgs(x,y) cerr << #x << " : " << x << " / " << #y << " : " << y << endl;
#define dbgv(v) cerr << #v << " : " << "[ "; for(auto it : v) cerr << it << ' '; cerr << ']' << endl;
#define here() cerr << "here" << endl;

void IO() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
}

#ifndef LOCAL
#include "grader.h"
#endif

#ifdef LOCAL
int N,Val,last=-1;
int Guess(int x){
	int ans;
	if(last==-1) ans=0;
	else if(abs(Val-x)==abs(Val-last)) ans=0;
	else if(abs(Val-x)<abs(Val-last)) ans=1;
	else ans=-1;
	last=x;
	return ans;
}
#endif

int HC(int N){
	int l=1,r=N;
	while(l<r){
		int len=r-l+1;
		int a,b; 
		if(len%3==0) a=l+len/3-1,b=r-len/3+1;
		else if(len%3==1) a=l+len/3,b=r-len/3+1;
		else a=l+len/3,b=r-len/3;
		a=l;

		int x=Guess(a);
		x=Guess(b);
		if(x==0) return (a+b)/2;
		if(x==1) l=(a+b)/2+1;
		else r=(a+b-1)/2;
	}
	return l;
}

#ifdef LOCAL
int main() {
    boost; IO();

    N=random(1,500);
    Val=random(1,N);
    assert(HC(N)==Val);

    return 0;
}
#endif

/* Careful!!!
    .Array bounds
    .Infinite loops
    .Uninitialized variables / empty containers
    .Multisets are shit

   Some insights:
    .Binary search
    .Graph representation
    .Write brute force code
    .Change your approach
*/
# Verdict Execution time Memory Grader output
1 Correct 30 ms 1260 KB Output is correct
# Verdict Execution time Memory Grader output
1 Incorrect 31 ms 1260 KB Output isn't correct
# Verdict Execution time Memory Grader output
1 Incorrect 31 ms 1260 KB Output isn't correct
# Verdict Execution time Memory Grader output
1 Incorrect 872 ms 8300 KB Output isn't correct - alpha = 0.000000000000