/**
* Author: Tenjin
* Created: 27.04.2022 18:58
* Why am I so stupid? :c
* Slishkom slab
**/
#include <bits/stdc++.h>
// #pragma GCC optimize("inline")
// #pragma GCC optimize("-fgcse,-fgcse-lm")
// #pragma GCC optimize("-ftree-pre,-ftree-vrp")
// #pragma GCC optimize("-ffast-math")
// #pragma GCC optimize("-fipa-sra")
// #pragma GCC optimize("-fpeephole2")
// #pragma GCC optimize("-fsched-spec")
// #pragma GCC optimize("Ofast,no-stack-protector")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
// #pragma GCC optimize("unroll-loops")
using namespace std;
#define ll long long
#define dl double long
#define ull unsigned long long
#define pr pair
#define vt vector
#define ff first
#define ss second
#define mp make_pair
#define sz(a) (int)a.size()
#define pb push_back
#define pf push_front
#define popB pop_back
#define popF pop_front
#define bit_count __builtin_popcount
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sp(x) fixed << setprecision(x)
template<typename T> T get_rand(T l, T r) {
random_device rd;
mt19937 gen(rd());
return uniform_int_distribution<T>(l, r)(gen);
}
template<typename T> T lcm(T a, T b) { return a * (b / __gcd(a, b)); }
template<class A> void read(vt<A>& v);
template<class A, size_t S> void read(array<A, S>& a);
template<class T> void read(T& x) { cin >> x; }
void read(double& d) { string t; read(t); d = stod(t); }
void read(long double& d) { string t; read(t); d = stold(t); }
template<class H, class... T> void read(H& h, T&... t) { read(h); read(t...); }
template<class A> void read(vt<A>& x) { for (auto& a : x) read(a); }
template<class A, size_t S> void read(array<A, S>& x) { for (auto& a : x) read(a); }
string to_string(char c) { return string(1, c); }
string to_string(bool b) { return b ? "true" : "false"; }
string to_string(const char* s) { return string(s); }
string to_string(string s) { return s; }
string to_string(vt<bool> v) { string res; for (int i = 0; i < sz(v); ++i) res += char('0' + v[i]); return res; }
template<size_t S> string to_string(bitset<S> b) { string res; for (int i = 0; i < S; ++i) res += char('0' + b[i]); return res; }
template<class T> string to_string(T v) { bool f = 1; string res; for (auto x : v) { if (!f) res += ' '; f = 0; res += to_string(x); } return res; }
template<class A> void write(A x) { cout << to_string(x); }
template<class H, class... T> void write(const H& h, const T&... t) { write(h); write(t...); }
void print() { write("\n"); }
template<class H, class... T> void print(const H& h, const T&... t) { write(h); if (sizeof...(t)) write(' '); print(t...); }
void freop(string s) {
freopen((s + ".in").c_str(), "r", stdin);
freopen((s + ".out").c_str(), "w", stdout);
}
const int MOD = 1e9 + 7;
const ll INF = 1e14;
const dl pi = acos(-1);
const dl eps = 1e-12;
const int sq = 700;
int dx[] = {-1, 0, 1, 0};
int dy[] = {0, -1, 0, 1};
/* ll vs int*/
const int N = 5e5 + 5;
const int M = 2e6 + 6;
int n;
vt<int> w, b;
int t[4 * N];
void upd(int pos, int val, int tl = 1, int tr = 2 * n, int v = 1) {
if(tl == tr) t[v] = val;
else {
int mid = (tl + tr) >> 1;
if(mid >= pos) upd(pos, val, tl, mid, v * 2);
else upd(pos, val, mid + 1, tr, v * 2 + 1);
t[v] = t[v * 2] + t[v * 2 + 1];
}
}
int get(int l, int r, int tl = 1, int tr = 2 * n, int v = 1) {
if(tl > r || tr < l) return 0;
if(tl >= l && tr <= r) return t[v];
int mid = (tl + tr) >> 1;
return get(l, r, tl, mid, v * 2) + get(l, r, mid + 1, tr, v * 2 + 1);
}
ll get(int i) {
vt<pr<int, int>> ord;
for(int j = 0; j < n; ++j) {
int X = w[j];
int Y = b[(j + i) % n];
if(X > Y) swap(X, Y);
ord.pb({X, Y});
}
sort(all(ord));
for(int j = 1; j <= 2 * n; ++j) upd(j, 0);
ll ans = 0;
for(int j = 0; j < n; ++j) {
ans += get(ord[j].ff, ord[j].ss);
// print(ans);
upd(ord[j].ss, 1);
}
return ans;
}
void solve() {
read(n);
for(int i = 1; i <= 2 * n; ++i) {
char s; read(s);
if(s == 'B') b.pb(i);
else w.pb(i);
}
ll res = 0;
if(get(0) <= get(n - 1)) {
int l = 0, r = n - 1;
ll need = get(n - 1);
while((r - l) >= 0) {
int mid = (r + l) >> 1;
ll cur = get(mid);
if(cur >= need && (mid != n - 1 && cur >= get(mid + 1))) r = mid - 1;
else l = mid + 1;
}
if(r < n - 1) r++;
res = get(r);
}
else {
int l = 0, r = n - 1;
ll need = get(0);
while((r - l) >= 0) {
int mid = (r + l) >> 1;
ll cur = get(mid);
if(cur >= need && (mid && cur >= get(mid - 1))) l = mid + 1;
else r = mid - 1;
}
if(l) l--;
res = get(l);
}
print(res);
}
int main() {
srand(time(NULL));
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
//freop("");
int t = 1;
//read(t);
for (int i = 1; i <= t; ++i) {
//write("Case #" + to_string(i) + ": ");
solve();
}
return 0;
}
Compilation message
monochrome.cpp: In function 'void freop(std::string)':
monochrome.cpp:73:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
73 | freopen((s + ".in").c_str(), "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
monochrome.cpp:74:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
74 | freopen((s + ".out").c_str(), "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Correct |
0 ms |
348 KB |
Output is correct |
| 5 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 6 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Correct |
0 ms |
348 KB |
Output is correct |
| 5 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 6 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Correct |
0 ms |
348 KB |
Output is correct |
| 5 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 6 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
348 KB |
Output is correct |
| 2 |
Correct |
0 ms |
348 KB |
Output is correct |
| 3 |
Correct |
0 ms |
348 KB |
Output is correct |
| 4 |
Correct |
0 ms |
348 KB |
Output is correct |
| 5 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
| 6 |
Halted |
0 ms |
0 KB |
- |
