| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1018838 | Boas | Counting Mushrooms (IOI20_mushrooms) | 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.
#include <bits/stdc++.h>
using namespace std;
int use_machine(std::vector<int> x);
#define loop(x, i) for (int i = 0; i < x; i++)
#define pb push_back
#define ALL(x) (x).begin(), (x).end()
typedef vector<int> vi;
typedef pair<int, int> ii;
typedef set<int> si;
typedef vector<vi> vvi;
int count_mushrooms(int n)
{
vi A = {0}, B;
int c1 = use_machine({0, 1});
int i = 2;
if (c1 == 1)
{
if (n == 2)
return 1;
B.pb(1);
int c2 = use_machine({1, 2});
i++;
if (c2 == 1)
A.pb(2);
else
B.pb(2);
}
else
{
A.pb(1);
}
int x = sqrt(n);
assert(x>=1);
while (max(A.size(), B.size()) < x)
{
if (A.size() >= 2)
{
if (i + 1 >= n)
break;
int res = use_machine({A[0], i, A[1], i + 1});
if (res == 0)
{
A.pb(i);
A.pb(i + 1);
}
else if (res == 1)
{
A.pb(i);
}
else if (res == 2)
{
A.pb(i + 1);
}
i += 2;
}
else
{
if (i + 1 >= n)
break;
int res = use_machine({B[0], i, B[1], i + 1});
if (res == 3)
{
A.pb(i);
A.pb(i + 1);
}
else if (res == 2)
{
A.pb(i);
}
else if (res == 1)
{
A.pb(i + 1);
}
i += 2;
}
}
if (i == n - 1)
{
if (use_machine({0, i}) == 0)
A.pb(i);
i++;
}
int res = A.size();
for (; i < n; i += x)
{
vi q;
if (A.size() >= x)
{
int l = min(x, n - i);
loop(l, j)
{
q.pb(A.at(j));
q.pb(i + j);
}
int c3 = use_machine(q);
if (c3 % 2 == 1) c3++;
res += l - (c3 / 2);
q.clear();
}
else
{
int l = min(x, n - i);
loop(l, j)
{
q.pb(B.at(j));
q.pb(i + j);
}
int c3 = use_machine(q);
if (c3 % 2 == 1) c3++;
res += (c3 / 2);
q.clear();
}
}
return res;
}
static char fmt_buffer[100000];
#define FMT_TO_STR(fmt, result) va_list vargs; va_start(vargs, fmt); \
vsnprintf(fmt_buffer, sizeof(fmt_buffer), fmt, vargs); \
va_end(vargs); fmt_buffer[sizeof(fmt_buffer)-1] = 0; \
std::string result(fmt_buffer);
static const int min_n = 2;
static const int max_n = 20000;
static const int max_qc = 20000;
static const int max_qs = 100000;
static const int species_A = 0;
static const int species_B = 1;
static int n;
static std::vector<int> species;
static int qc, qs;
static inline void error_if(bool cond, std::string message) {
if (cond) {
printf("%s\n", message.c_str());
exit(0);
}
}
static inline void wrong_if(bool cond, std::string message) {
error_if(cond, "Wrong Answer: "+message);
}
int use_machine(std::vector<int> x) {
const int xs = x.size();
wrong_if(xs < 2, "Too small array for query.");
wrong_if(xs > n, "Too large array for query.");
qc++;
wrong_if(qc > max_qc, "Too many queries.");
qs += xs;
wrong_if(qs > max_qs, "Too many total array sizes as queries.");
for (int i = 0; i < xs; i++)
wrong_if(x[i] < 0 || n - 1 < x[i], "Invalid value in the query array.");
std::vector<bool> used(n, false);
for (int i = 0; i < xs; i++) {
wrong_if(used[x[i]], "Duplicate value in the query array.");
used[x[i]] = true;
}
int diffs = 0;
for (int i = 1; i < xs; i++)
diffs += int(species[x[i]] != species[x[i-1]]);
return diffs;
}
#ifdef __GNUC__
__attribute__ ((format(printf, 2, 3)))
#endif
static inline void check_input(bool cond, const char* message_fmt, ...) {
FMT_TO_STR(message_fmt, message);
error_if(!cond, "Invalid input: "+message);
}
int main() {
check_input(1 == scanf("%d", &n), "Could not read n.");
check_input(min_n <= n, "n must not be less than %d, but it is %d.", min_n, n);
check_input(n <= max_n, "n must not be greater than %d, but it is %d.", max_n, n);
species.resize(n);
for (int i = 0; i < n; i++) {
check_input(1 == scanf("%d", &species[i]), "Could not read species element [%d].", i);
check_input(species[i]==species_A || species[i] == species_B,
"Species elements must be %d or %d, but species element [%d] is %d.", species_A, species_B, i, species[i]);
}
check_input(species[0] == species_A, "Species element [%d] must be %d.", 0, species_A);
// Postponed closing standard input in order to allow interactive usage of the grader.
qc = 0;
qs = 0;
int answer = count_mushrooms(n);
printf("%d\n", answer);
fclose(stdout);
fclose(stdin);
return 0;
}