| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 591837 | tutis | Flight to the Ford (BOI22_communication) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#pragma GCC optimize ("O3")
#pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
int prob = 500;
#include "communication.h"
struct intervalset
{
int sz = 0;
vector<pair<int, int>>S;//sorted, disjoint
intervalset()
{
}
intervalset(int N)
{
sz = N;
S.push_back({1, N});
}
void append(pair<int, int> v)
{
sz += v.second - v.first + 1;
if (S.empty())
S.push_back(v);
else {
assert(v.first > S.back().second);
if (v.first == S.back().second + 1)
S.back().second = v.second;
else
S.push_back(v);
}
}
pair<intervalset, intervalset> split(int k)
{ //k,sz-k
intervalset A;
intervalset B;
for (pair<int, int>i : S)
{
if (i.second - i.first + 1 <= k)
{
A.append(i);
k -= i.second - i.first + 1;
}
else if (k <= 0)
{
B.append(i);
}
else
{
A.append({i.first, i.first + k - 1});
B.append({i.first + k, i.second});
k = 0;
}
}
return {A, B};
}
int kth(int k)
{
for (pair<int, int>i : S)
{
if (i.second - i.first + 1 < k)
{
k -= i.second - i.first + 1;
}
else
{
return i.first + (k - 1);
}
}
assert(false);
return 0;
}
int kelintas(int x)
{
int r = 0;
for (pair<int, int>i : S)
{
if (i.second < x)
r += (i.second - i.first + 1);
else if (x < i.first)
return 0;
else
return r + (x - i.first + 1);
}
return 0;
}
intervalset(const intervalset &A, const intervalset &B)
{
const vector<pair<int, int>>&a = A.S;
const vector<pair<int, int>>&b = B.S;
int i = 0;
int j = 0;
while (i < (int)a.size() && j < (int)b.size())
{
if (a[i].first < b[j].first)
append(a[i++]);
else
append(b[j++]);
}
while (i < (int)a.size())
append(a[i++]);
while (j < (int)b.size())
append(b[j++]);
}
};
const int mxsum = 100;
pair<int, pair<int, int>> K[mxsum][mxsum];
bool prec = false;
pair<int, int> getbest(int A, int B)
{
assert(A + B < mxsum);
if (prec == false)
{
prec = true;
for (int sum = 0; sum < mxsum; sum++)
for (int a = 0; a <= sum; a++)
{
int b = sum - a;
K[a][b] = {1000, {0, 0}};
}
for (int sum = 0; sum < mxsum; sum++)
{
if (sum <= 2)
{
for (int a = 0; a <= sum; a++) {
int b = sum - a;
K[a][b] = {0, {0, 0}};
}
}
else {
int rep = 1;
if (sum <= 10)
rep = 10;
for (int r = 0; r < rep; r++)
for (int a = 0; a <= sum; a++)
{
int b = sum - a;
for (int a0 = 0; a0 <= a; a0++)
{
for (int b0 = 0; b0 <= b; b0++)
{
int a1 = a - a0;
int b1 = b - b0;
int a_ = a0 + b0;
int b_ = a1;
int a__ = a1 + b1;
int b__ = a0;
pair<int, pair<int, int>> gal =
{1 + max(K[a_][b_].first, K[a__][b__].first), {a0, b0}};
K[a][b] = min(K[a][b], gal);
}
}
}
}
}
}
return K[A][B].second;
}
vector<pair<int, int>>eil;
void encode(int N, int X)
{
intervalset A(N);
intervalset B;
mt19937 rng(0);
while (A.sz + B.sz > 2)
{
eil.push_back({A.sz, B.sz});
int a0 = A.sz / 2;
int b0 = B.sz / 2;
if (A.sz + B.sz < mxsum)
{
pair<int, int>c = getbest(A.sz, B.sz);
a0 = c.first;
b0 = c.second;
}
eil.push_back({a0, b0});
eil.push_back({0, 0});
intervalset C(A, B);
int ka = A.kelintas(X);
int kb = B.kelintas(X);
int s = 1;
if (ka != 0 && ka <= a0)
s = 0;
if (kb != 0 && kb <= b0)
s = 0;
pair<intervalset, intervalset>A_ = A.split(a0);
pair<intervalset, intervalset>B_ = B.split(b0);
int r = send(s);
if (r == 0)
{
A = intervalset(A_.first, B_.first);
B = A_.second;
}
else
{
A = intervalset(A_.second, B_.second);
B = A_.first;
}
}
}
ld phi = (1 + sqrtl(5)) / 2;
pair<int, int> decode(int N)
{
intervalset A(N);
intervalset B;
mt19937 rng(0);
while (A.sz + B.sz > 2)
{
int b0 = B.sz / 2;
int a0 = A.sz / 2;
if (A.sz + B.sz < mxsum)
{
pair<int, int>c = getbest(A.sz, B.sz);
a0 = c.first;
b0 = c.second;
}
pair<intervalset, intervalset>A_ = A.split(a0);
pair<intervalset, intervalset>B_ = B.split(b0);
int r = receive();
if (r == 0)
{
A = intervalset(A_.first, B_.first);
B = A_.second;
}
else
{
A = intervalset(A_.second, B_.second);
B = A_.first;
}
}
if (A.sz == 0)
return {B.S[0].first, B.S.back().second};
if (B.sz == 0)
return {A.S[0].first, A.S.back().second};
return {A.S[0].first, B.S[0].first};
}
int main()
{
int mx = 0;
vector<pair<int, int>>ilg;
for (int test = 0; test < 10000; test++)
{
int N = 1e9;
int X = (asdasdasdasdasd() % N) + 1;
encode(N, X);
pair<int, int>a = decode(N);
assert(a.first >= 1 && a.first <= N && a.second >= 1 && a.second <= N);
assert(a.first == X || a.second == X);
if (kiekis > mx)
{
ilg = eil;
mx = kiekis;
}
kiekis = 0;
eil.clear();
}
cout << mx << endl;
}