#include "bits/stdc++.h"
using namespace std;
#define FAST ios_base::sync_with_stdio(false); cin.tie(0);
#define pb push_back
#define eb emplace_back
#define ins insert
#define f first
#define s second
#define cbr cerr<<"hi\n"
#define mmst(x, v) memset((x), v, sizeof ((x)))
#define siz(x) ll(x.size())
#define all(x) (x).begin(), (x).end()
#define lbd(x,y) (lower_bound(all(x),y)-x.begin())
#define ubd(x,y) (upper_bound(all(x),y)-x.begin())
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); //can be used by calling rng() or shuffle(A, A+n, rng)
inline long long rand(long long x, long long y) { return rng() % (y+1-x) + x; } //inclusivesss
string inline to_string(char c) {string s(1,c);return s;} template<typename T> inline T gcd(T a,T b){ return a==0?llabs(b):gcd(b%a,a); }
using ll=long long;
using ld=long double;
#define FOR(i,s,e) for(ll i=s;i<=ll(e);++i)
#define DEC(i,s,e) for(ll i=s;i>=ll(e);--i)
using pi=pair<ll,ll>; using spi=pair<ll,pi>; using dpi=pair<pi,pi>;
long long LLINF = 1e18;
int INF = 1e9+1e6;
#define MAXN (400006)
ll n, b, w, ans;
string A;
deque<ll> B, W;
int main() {
FAST
cin>>n>>A; n *= 2;
b = count(all(A), 'B'), w = count(all(A), 'W');
FOR(i,0,n-1) if(A[i] == 'B') {
-- b;
if(W.size() > b) { // must merge
ll minus = lbd(B, W[0]);
W.pop_front();
ans += siz(W) + siz(B) - minus;
} else {
B.eb(i);
}
if(B.size() > w) {
assert(0);
}
} else {
-- w;
if(B.size() > w) {
ll minus = lbd(W, B[0]);
B.pop_front();
ans += siz(W) + siz(B) - minus;
} else {
W.eb(i);
}
if(W.size() > b) {
assert(0);
}
}
assert(W.empty() && B.empty());
cout<<ans<<'\n';
}
Compilation message
monochrome.cpp: In function 'int main()':
monochrome.cpp:38:15: warning: comparison of integer expressions of different signedness: 'std::deque<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
38 | if(W.size() > b) { // must merge
| ~~~~~~~~~^~~
monochrome.cpp:45:15: warning: comparison of integer expressions of different signedness: 'std::deque<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
45 | if(B.size() > w) {
| ~~~~~~~~~^~~
monochrome.cpp:50:15: warning: comparison of integer expressions of different signedness: 'std::deque<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
50 | if(B.size() > w) {
| ~~~~~~~~~^~~
monochrome.cpp:57:15: warning: comparison of integer expressions of different signedness: 'std::deque<long long int>::size_type' {aka 'long unsigned int'} and 'll' {aka 'long long int'} [-Wsign-compare]
57 | if(W.size() > b) {
| ~~~~~~~~~^~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
364 KB |
Output is correct |
| 2 |
Correct |
1 ms |
364 KB |
Output is correct |
| 3 |
Correct |
1 ms |
364 KB |
Output is correct |
| 4 |
Correct |
1 ms |
364 KB |
Output is correct |
| 5 |
Incorrect |
1 ms |
364 KB |
Output isn't correct |
| 6 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
364 KB |
Output is correct |
| 2 |
Correct |
1 ms |
364 KB |
Output is correct |
| 3 |
Correct |
1 ms |
364 KB |
Output is correct |
| 4 |
Correct |
1 ms |
364 KB |
Output is correct |
| 5 |
Incorrect |
1 ms |
364 KB |
Output isn't correct |
| 6 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
364 KB |
Output is correct |
| 2 |
Correct |
1 ms |
364 KB |
Output is correct |
| 3 |
Correct |
1 ms |
364 KB |
Output is correct |
| 4 |
Correct |
1 ms |
364 KB |
Output is correct |
| 5 |
Incorrect |
1 ms |
364 KB |
Output isn't correct |
| 6 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
1 ms |
364 KB |
Output is correct |
| 2 |
Correct |
1 ms |
364 KB |
Output is correct |
| 3 |
Correct |
1 ms |
364 KB |
Output is correct |
| 4 |
Correct |
1 ms |
364 KB |
Output is correct |
| 5 |
Incorrect |
1 ms |
364 KB |
Output isn't correct |
| 6 |
Halted |
0 ms |
0 KB |
- |
