| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1313265 | BigBadBully | Counting Mushrooms (IOI20_mushrooms) | C++20 | 0 ms | 0 KiB |
#include <bits/stdc++.h>
#include "mushrooms.h"
using namespace std;
const int inf = 1e9;
#define pii pair<int,int>
#define ff first
#define ss second
int count_mushrooms(int n) {
int bl = 100;
vector<int> v(n,1);
v[0] = 0;
bool dif = 0;
int st = 1;
vector<int> wh[2];
wh[0].push_back(0);
for(;st<n;st++)
{
v[st] = v[st-1];
if(use_machine({st-1,st}))
dif = 1,v[st] = 1-v[st-1];
wh[v[st]].push_back(st);
if(max(wh[0].size(),wh[1].size())>bl)
break;
}
st++;
int sum = count(v.begin(),v.end(),0);
function<int(int,int)> calc = [&](int l,int r)
{
vector<int> que;
array<int,2> idx = {0,0};
bool gurt = 0;
function<void()>f = [&](){
for(int it = 0;it < 2;it++)
if(wh[it].size()==max(wh[0].size(),wh[1].size()))
{
que.push_back(wh[it][idx[it]++]);
break;
}
};
f();
for(int i = l; i <= r; i++)
{
que.push_back(i);
f();
}
int val = use_machine(que)/2;
int len = r-l+1;
if(wh[1].size()>wh[0].size())
return val;
return len-val;
};
for(;st<n;st+=bl)
sum+=calc(st,min(st+bl-1,n-1));
return sum;
}
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() {
srand(time(0));
n = rand()%1000+2;
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,0);
for (int i = 1; i < n; i++) {
species[i]=rand()%2;
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);
if(count(species.begin(),species.end(),0) != answer)
{
cout << "Wrong answer\n"<<answer<<' '<<count(species.begin(),species.end(),0)<<'\n';
exit(0);
}
printf("%d\n%d\n", answer, qc);
fclose(stdout);
fclose(stdin);
return 0;
}