#include <bits/stdc++.h>
#ifndef DEBUG
#include "books.h"
#endif
using namespace std;
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define all(a) (a).begin(), (a).end()
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
using ld = long double;
template<typename T1, typename T2> bool chkmin(T1 &x, T2 y) {
return y < x ? (x = y, true) : false;
}
template<typename T1, typename T2> bool chkmax(T1 &x, T2 y) {
return y > x ? (x = y, true) : false;
}
void debug_out() {
cerr << endl;
}
template<typename T1, typename... T2> void debug_out(T1 A, T2... B) {
cerr << ' ' << A;
debug_out(B...);
}
template<typename T> void mdebug_out(T* a, int n) {
for (int i = 0; i < n; ++i) {
cerr << a[i] << ' ';
}
cerr << endl;
}
#ifdef DEBUG
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define mdebug(a, n) cerr << #a << ": ", mdebug_out(a, n)
#else
#define debug(...) 1337
#define mdebug(a, n) 1337
#endif
template<typename T> ostream& operator << (ostream& stream, const vector<T> &v) {
for (auto& x : v) {
stream << x << ' ';
}
return stream;
}
template<typename T1, typename T2> ostream& operator << (ostream& stream, const pair<T1, T2>& p) {
return stream << p.first << ' ' << p.second;
}
const int maxN = 1000006;
const int INF32 = 1e9;
int n;
namespace fnw {
int f[maxN];
void add(int i) {
for (++i; i < maxN; i += i & -i) {
++f[i];
}
}
int pref(int i) {
int ans = 0;
for (++i; i >= 1; i -= i & -i) {
ans += f[i];
}
return ans;
}
}
namespace dsu {
int q[maxN];
void reset() {
memset(q, 255, sizeof q);
}
int gt(int x) {
return q[x] < 0 ? x : q[x] = gt(q[x]);
}
bool un(int x, int y) {
x = gt(x);
y = gt(y);
if (x == y) return false;
if (-q[x] < -q[y]) swap(x, y);
q[x] += q[y];
q[y] = x;
return true;
}
}
ll minimum_walk(vector<int> p, int s) {
n = p.size();
ll ans = 0;
int mn = 1e9;
int mx = -1e9;
dsu::reset();
for (int i = 0; i + 1 < n; ++i) {
fnw::add(p[i]);
int r = i + 1 - fnw::pref(i);
if (r > 0) {
ans += 2 * r;
dsu::un(i, i + 1);
chkmin(mn, i);
chkmax(mx, i + 1);
}
}
int mnD = INF32;
for (int i = 0; i < n; ++i) {
if (p[i] != i && (i == 0 || dsu::gt(i) != dsu::gt(i - 1) || i == n - 1 || dsu::gt(i) != dsu::gt(i + 1))) {
chkmin(mnD, labs(i - s)); 1
}
}
if (mnD == INF32) return 0;
for (int i = mn; i < mx; ++i) {
if (dsu::un(i, i + 1)) {
ans += 2;
}
}
return ans + 2 * mnD;
}
#ifdef DEBUG
int32_t main() {
#ifdef DEBUG
freopen("in", "r", stdin);
#endif
ios::sync_with_stdio(0);
cin.tie(0);
int n, s;
cin >> n >> s;
vector<int> p(n);
for (auto& x : p) cin >> x;
cout << minimum_walk(p, s) << '\n';
return 0;
}
#endif
Compilation message
books.cpp: In function 'll minimum_walk(std::vector<int>, int)':
books.cpp:114:108: error: expected ';' before '}' token
114 | chkmin(mnD, labs(i - s)); 1
| ^
| ;
115 | }
| ~
books.cpp:114:107: warning: statement has no effect [-Wunused-value]
114 | chkmin(mnD, labs(i - s)); 1
| ^
