#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx,popcnt,sse4,abm")
#include <bits/stdc++.h>
using namespace std;
#ifndef WAIMAI
#include "mushrooms.h"
#endif
#ifdef WAIMAI
#define debug(HEHE...) cout << "[" << #HEHE << "] : ", dout(HEHE)
void dout() {cout << '\n';}
template<typename T, typename...U>
void dout(T t, U...u) {cout << t << (sizeof...(u) ? ", " : ""), dout(u...);}
#else
#define debug(...) 7122
#endif
#define ll long long
#define Waimai ios::sync_with_stdio(false), cin.tie(0)
#define FOR(x,a,b) for (int x = a, I = b; x <= I; x++)
#define pb emplace_back
#define F first
#define S second
#ifdef WAIMAI
int use_machine(vector<int> x);
#endif
const int K = 0;
int count_mushrooms(int n) {
int ans = 0, mx = min(n - 1, K);
vector<int> id[2];
id[0].pb(0);
FOR (i, 1, mx) {
vector<int> v;
v.pb(0), v.pb(i);
int cnt = use_machine(v);
id[cnt].pb(i);
if (max(id[0].size(), id[1].size()) == 2) break;
}
if (id[0].size() == 2) {
int l = id[0].size() + id[1].size(), r = min(mx, l + 1);
while (l <= mx) {
vector<int> v;
if (l == r) {
v.pb(0), v.pb(l);
int cnt = use_machine(v);
id[cnt].pb(l);
} else {
v.pb(id[0][0]), v.pb(l), v.pb(id[0][1]), v.pb(r);
int cnt = use_machine(v);
id[cnt & 1].pb(r);
id[cnt >> 1 & 1].pb(l);
}
l = r + 1;
r = min(mx, l + 1);
}
} else if (id[1].size() == 2) {
int l = id[0].size() + id[1].size(), r = min(mx, l + 1);
while (l <= mx) {
vector<int> v;
if (l == r) {
v.pb(0), v.pb(l);
int cnt = use_machine(v);
id[cnt].pb(l);
} else {
v.pb(id[1][0]), v.pb(l), v.pb(id[1][1]), v.pb(r);
int cnt = use_machine(v);
id[!(cnt & 1)].pb(r);
id[!(cnt >> 1 & 1)].pb(l);
}
l = r + 1;
r = min(mx, l + 1);
}
}
ans += id[0].size();
int l = mx + 1, r;
while (l < n) {
if (id[0].size() >= id[1].size()) {
r = min<int>(n - 1, l + id[0].size() - 1);
vector<int> v;
for (int j = l; j <= r; j++) {
v.pb(id[0][j - l]);
v.pb(j);
}
int cnt = use_machine(v);
ans += (r - l + 1) - (cnt + 1) / 2;
id[cnt & 1].pb(r);
} else {
r = min<int>(n - 1, l + id[1].size() - 1);
vector<int> v;
for (int j = l; j <= r; j++) {
v.pb(id[1][j - l]);
v.pb(j);
}
int cnt = use_machine(v);
ans += (cnt + 1) / 2;
id[!(cnt & 1)].pb(r);
}
l = r + 1;
}
return ans;
}
/*
in1
3
0 1 1
out1
1
2
in2
4
0 1 0 0
out2
3
2
*/
#ifdef WAIMAI
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; \
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 vector<int> species;
static int qc, qs;
static inline void error_if(bool cond, string message) {
if (cond) {
printf("%s\n", message.c_str());
exit(0);
}
}
static inline void wrong_if(bool cond, string message) {
error_if(cond, "Wrong Answer: "+message);
}
int use_machine(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.");
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%d\n", answer, qc);
fclose(stdout);
fclose(stdin);
return 0;
}
#endif
