#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
//#pragma GCC optimization("g", on)
//#pragma GCC optimization("03")
//#pragma comment(linker, "/stack:200000000")
//#pragma GCC optimize("Ofast")
//#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")
#define aboba ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define br break;
#define sp " "
#define en "\n"
#define pb push_back
#define sz(a) int(a.size())
#define bg begin()
#define ed end()
#define in insert
#define ss second
#define ff first
#define setp(a) cout << fixed; cout << setprecision(a);
#define all(v) v.begin(), v.end()
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> pll;
typedef double db;
typedef tree<
long long,
null_type,
less_equal<long long>,
rb_tree_tag,
tree_order_statistics_node_update> orset;
void freopen(string s) { freopen((s + ".in").c_str(), "r", stdin); freopen((s + ".out").c_str(), "w", stdout); }
ll bp(ll x, ll y, ll z) { ll res = 1; while (y) { if (y & 1) { res = (res * x) % z; y--; } x = (x * x) % z; y >>= 1; } return res; }
// C(n, k) = ((fact[n] * bp(fact[k], mod - 2)) % mod * bp(fact[n - k], mod - 2)) % mod;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
ll lcm(ll a, ll b) { return (a / __gcd(a, b)) * b; }
const ll N = 2e5 + 11;
const ll inf = 1e18 + 7;
ll tt = 1;
ll n;
string s;
ll get(bool f) {
ll ans = 0, num = 1;
for (int i = 1;i <= n;i++) {
if (f == (s[i] == 'R' ? 0 : 1)) {
ans += abs(i - num);
num += 2;
}
}
return ans;
}
void solve() {
cin >> n;
cin >> s;
s = ' ' + s;
if (n <= 15) {
ll ans = inf;
for (int i = 0;i < (1 << n);i++) {
string t = s;
for (int j = 0;j < n - 1;j++) {
if (i & (1 << j)) {
swap(t[j + 1], t[j + 2]);
}
}
bool f = 0;
for (int j = 1;j < n;j++) {
if (t[j] == t[j + 1]) f = 1;
}
if (!f) {
ans = min(ans, ll(__builtin_popcount(i)));
}
}
cout << (ans == inf ? -1 : ans) << en;
return;
}
ll cnt = 0, cnt1 = 0;
for (int i = 1;i <= n;i++) {
(s[i] == 'R' ? cnt : cnt1)++;
}
if (abs(cnt - cnt1) > 1) {
cout << -1 << en;
return;
}
ll ans = inf;
if (cnt == cnt1) {
ans = min(ans, get(0));
ans = min(ans, get(1));
} else if (cnt < cnt1) {
ans = min(ans, get(1));
} else {
ans = min(ans, get(0));
}
cout << ans << en;
}
int main() {
aboba
// freopen("cownomics");
// precalc();
// cin >> tt;
for (int i = 1;i <= tt;i++) {
solve();
}
}
Compilation message
joi2019_ho_t3.cpp: In function 'void freopen(std::string)':
joi2019_ho_t3.cpp:47:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
47 | void freopen(string s) { freopen((s + ".in").c_str(), "r", stdin); freopen((s + ".out").c_str(), "w", stdout); }
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
joi2019_ho_t3.cpp:47:75: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
47 | void freopen(string s) { freopen((s + ".in").c_str(), "r", stdin); freopen((s + ".out").c_str(), "w", stdout); }
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Incorrect |
1 ms |
344 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Incorrect |
1 ms |
344 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
344 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 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
1 ms |
348 KB |
Output is correct |
9 |
Correct |
0 ms |
348 KB |
Output is correct |
10 |
Correct |
0 ms |
348 KB |
Output is correct |
11 |
Correct |
0 ms |
348 KB |
Output is correct |
12 |
Correct |
0 ms |
348 KB |
Output is correct |
13 |
Correct |
0 ms |
348 KB |
Output is correct |
14 |
Correct |
0 ms |
348 KB |
Output is correct |
15 |
Correct |
0 ms |
344 KB |
Output is correct |
16 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Incorrect |
1 ms |
344 KB |
Output isn't correct |
5 |
Halted |
0 ms |
0 KB |
- |