// #pragma GCC optimize("O3,Ofast,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
using namespace std;
#define int long long int
#define MP make_pair
#define pb push_back
#define REP(i,n) for(int i = 0; (i) < (n); (i)++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
void fastio() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
}
const double EPS = 0.00001;
const int INF = 1e9+500;
const int N = 3e5+5;
const int ALPH = 26;
const int LGN = 25;
constexpr int MOD = 1e9+7;
int n,m,q;
vector<int> pw;
vector<int> b,w;
int getSum(int l, int r) {
if(l <= r) {
return pw[r] - ((l > 0) ? pw[l - 1] : 0);
}
return pw[r] + (pw[2*n-1] - ((l > 0) ? pw[l - 1] : 0));
}
int dif(int l, int r) {
if(l <= r) return r - l + 1;
else return 2*n + r - l + 1;
}
int calc_k(int k) {
int ret = 0;
for(int i = 0; i<n; i++) {
int j = (i + k) % n;
int wu = getSum(w[i], b[j]) - 1;
int wd = n - 1 - wu, bu = dif(w[i], b[j]) - 2 - wu;
int bd = n - 1 - bu;
// cout << " wi:" << w[i] << " bj:" << b[j] << " wu:" << wu << " wd:" << wd << " bu:" << bu << " bd:" << bd << "\n";
ret += min(wu, bd) + min(wd, bu);
}
// cout << ret << "\n";
return ret / 2;
}
int ceil_div(int x, int y) {
return (x - 1) / y + 1;
}
inline void solve() {
cin >> n;
string s;
cin >> s;
pw.assign(2*n + 3, 0);
pw[0] = s[0] == 'W';
for(int i = 0; i<2*n; i++) {
if(s[i] == 'B') b.pb(i);
else w.pb(i);
}
for(int i = 1; i<2*n; i++) {
pw[i] = pw[i - 1] + (s[i] == 'W');
}
int tl = 0, tr = n - 1;
while(tl < tr) {
int tm1 = tl + (tr - tl) / 3;
int tm2 = tl + ceil_div(2*(tr - tl), 3);
if(calc_k(tm1) < calc_k(tm2)) {
tl = tm1 + 1;
}
else {
tr = tm2 - 1;
}
}
cout << calc_k(tl) << "\n";
}
signed main() {
fastio();
int test = 1;
//cin>>test;
while(test--) {
solve();
}
}
# |
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 |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
600 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
1 ms |
344 KB |
Output is correct |
8 |
Correct |
0 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 |
344 KB |
Output is correct |
12 |
Correct |
1 ms |
348 KB |
Output is correct |
13 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
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 |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
600 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
1 ms |
344 KB |
Output is correct |
8 |
Correct |
0 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 |
344 KB |
Output is correct |
12 |
Correct |
1 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 |
1 ms |
348 KB |
Output is correct |
16 |
Correct |
0 ms |
348 KB |
Output is correct |
17 |
Correct |
1 ms |
348 KB |
Output is correct |
18 |
Correct |
1 ms |
348 KB |
Output is correct |
19 |
Correct |
0 ms |
348 KB |
Output is correct |
20 |
Correct |
1 ms |
344 KB |
Output is correct |
21 |
Correct |
0 ms |
344 KB |
Output is correct |
22 |
Correct |
1 ms |
348 KB |
Output is correct |
23 |
Correct |
1 ms |
348 KB |
Output is correct |
24 |
Correct |
0 ms |
348 KB |
Output is correct |
25 |
Correct |
0 ms |
348 KB |
Output is correct |
26 |
Correct |
0 ms |
348 KB |
Output is correct |
27 |
Correct |
0 ms |
344 KB |
Output is correct |
28 |
Correct |
1 ms |
348 KB |
Output is correct |
29 |
Correct |
1 ms |
348 KB |
Output is correct |
30 |
Correct |
1 ms |
600 KB |
Output is correct |
31 |
Correct |
0 ms |
348 KB |
Output is correct |
32 |
Correct |
1 ms |
344 KB |
Output is correct |
33 |
Correct |
1 ms |
344 KB |
Output is correct |
# |
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 |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
600 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
1 ms |
344 KB |
Output is correct |
8 |
Correct |
0 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 |
344 KB |
Output is correct |
12 |
Correct |
1 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 |
1 ms |
348 KB |
Output is correct |
16 |
Correct |
0 ms |
348 KB |
Output is correct |
17 |
Correct |
1 ms |
348 KB |
Output is correct |
18 |
Correct |
1 ms |
348 KB |
Output is correct |
19 |
Correct |
0 ms |
348 KB |
Output is correct |
20 |
Correct |
1 ms |
344 KB |
Output is correct |
21 |
Correct |
0 ms |
344 KB |
Output is correct |
22 |
Correct |
1 ms |
348 KB |
Output is correct |
23 |
Correct |
1 ms |
348 KB |
Output is correct |
24 |
Correct |
0 ms |
348 KB |
Output is correct |
25 |
Correct |
0 ms |
348 KB |
Output is correct |
26 |
Correct |
0 ms |
348 KB |
Output is correct |
27 |
Correct |
0 ms |
344 KB |
Output is correct |
28 |
Correct |
1 ms |
348 KB |
Output is correct |
29 |
Correct |
1 ms |
348 KB |
Output is correct |
30 |
Correct |
1 ms |
600 KB |
Output is correct |
31 |
Correct |
0 ms |
348 KB |
Output is correct |
32 |
Correct |
1 ms |
344 KB |
Output is correct |
33 |
Correct |
1 ms |
344 KB |
Output is correct |
34 |
Correct |
1 ms |
348 KB |
Output is correct |
35 |
Correct |
1 ms |
548 KB |
Output is correct |
36 |
Correct |
1 ms |
348 KB |
Output is correct |
37 |
Correct |
1 ms |
348 KB |
Output is correct |
38 |
Correct |
1 ms |
348 KB |
Output is correct |
39 |
Correct |
1 ms |
596 KB |
Output is correct |
40 |
Correct |
1 ms |
348 KB |
Output is correct |
41 |
Correct |
1 ms |
348 KB |
Output is correct |
42 |
Correct |
1 ms |
348 KB |
Output is correct |
43 |
Correct |
1 ms |
348 KB |
Output is correct |
44 |
Correct |
1 ms |
348 KB |
Output is correct |
45 |
Correct |
1 ms |
348 KB |
Output is correct |
46 |
Correct |
2 ms |
348 KB |
Output is correct |
47 |
Correct |
1 ms |
348 KB |
Output is correct |
48 |
Correct |
1 ms |
348 KB |
Output is correct |
49 |
Correct |
1 ms |
348 KB |
Output is correct |
50 |
Correct |
1 ms |
356 KB |
Output is correct |
51 |
Correct |
1 ms |
348 KB |
Output is correct |
52 |
Correct |
1 ms |
348 KB |
Output is correct |
# |
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 |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
600 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
348 KB |
Output is correct |
7 |
Correct |
1 ms |
344 KB |
Output is correct |
8 |
Correct |
0 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 |
344 KB |
Output is correct |
12 |
Correct |
1 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 |
1 ms |
348 KB |
Output is correct |
16 |
Correct |
0 ms |
348 KB |
Output is correct |
17 |
Correct |
1 ms |
348 KB |
Output is correct |
18 |
Correct |
1 ms |
348 KB |
Output is correct |
19 |
Correct |
0 ms |
348 KB |
Output is correct |
20 |
Correct |
1 ms |
344 KB |
Output is correct |
21 |
Correct |
0 ms |
344 KB |
Output is correct |
22 |
Correct |
1 ms |
348 KB |
Output is correct |
23 |
Correct |
1 ms |
348 KB |
Output is correct |
24 |
Correct |
0 ms |
348 KB |
Output is correct |
25 |
Correct |
0 ms |
348 KB |
Output is correct |
26 |
Correct |
0 ms |
348 KB |
Output is correct |
27 |
Correct |
0 ms |
344 KB |
Output is correct |
28 |
Correct |
1 ms |
348 KB |
Output is correct |
29 |
Correct |
1 ms |
348 KB |
Output is correct |
30 |
Correct |
1 ms |
600 KB |
Output is correct |
31 |
Correct |
0 ms |
348 KB |
Output is correct |
32 |
Correct |
1 ms |
344 KB |
Output is correct |
33 |
Correct |
1 ms |
344 KB |
Output is correct |
34 |
Correct |
1 ms |
348 KB |
Output is correct |
35 |
Correct |
1 ms |
548 KB |
Output is correct |
36 |
Correct |
1 ms |
348 KB |
Output is correct |
37 |
Correct |
1 ms |
348 KB |
Output is correct |
38 |
Correct |
1 ms |
348 KB |
Output is correct |
39 |
Correct |
1 ms |
596 KB |
Output is correct |
40 |
Correct |
1 ms |
348 KB |
Output is correct |
41 |
Correct |
1 ms |
348 KB |
Output is correct |
42 |
Correct |
1 ms |
348 KB |
Output is correct |
43 |
Correct |
1 ms |
348 KB |
Output is correct |
44 |
Correct |
1 ms |
348 KB |
Output is correct |
45 |
Correct |
1 ms |
348 KB |
Output is correct |
46 |
Correct |
2 ms |
348 KB |
Output is correct |
47 |
Correct |
1 ms |
348 KB |
Output is correct |
48 |
Correct |
1 ms |
348 KB |
Output is correct |
49 |
Correct |
1 ms |
348 KB |
Output is correct |
50 |
Correct |
1 ms |
356 KB |
Output is correct |
51 |
Correct |
1 ms |
348 KB |
Output is correct |
52 |
Correct |
1 ms |
348 KB |
Output is correct |
53 |
Correct |
60 ms |
7640 KB |
Output is correct |
54 |
Correct |
61 ms |
8148 KB |
Output is correct |
55 |
Correct |
59 ms |
7652 KB |
Output is correct |
56 |
Correct |
64 ms |
7652 KB |
Output is correct |
57 |
Correct |
62 ms |
7524 KB |
Output is correct |
58 |
Correct |
57 ms |
7784 KB |
Output is correct |
59 |
Correct |
65 ms |
7652 KB |
Output is correct |
60 |
Correct |
57 ms |
7372 KB |
Output is correct |
61 |
Correct |
58 ms |
7336 KB |
Output is correct |
62 |
Correct |
57 ms |
7468 KB |
Output is correct |
63 |
Correct |
57 ms |
7652 KB |
Output is correct |
64 |
Correct |
61 ms |
8676 KB |
Output is correct |
65 |
Correct |
56 ms |
7204 KB |
Output is correct |
66 |
Correct |
58 ms |
8676 KB |
Output is correct |
67 |
Correct |
58 ms |
8652 KB |
Output is correct |
68 |
Correct |
61 ms |
8472 KB |
Output is correct |
69 |
Correct |
60 ms |
8036 KB |
Output is correct |
70 |
Correct |
56 ms |
7020 KB |
Output is correct |
71 |
Correct |
60 ms |
8872 KB |
Output is correct |
72 |
Correct |
62 ms |
8932 KB |
Output is correct |
73 |
Correct |
59 ms |
7892 KB |
Output is correct |