#include <bits/stdc++.h>
#define all(x) (x).begin(),(x).end()
using namespace std;
using ll = long long;
using ld = long double;
//#define int ll
#define sz(x) ((int)(x).size())
using pii = pair<int,int>;
using tii = tuple<int,int,int>;
const int nmax = 2e5 + 5;
#define lsb(x) (x & -x)
struct AIB {
vector<int> tree;
void init(int n) { tree.assign(n + 5, 0); }
void upd(int p, int x) {
while(p < sz(tree)) tree[p] += x, p += lsb(p);
}
int query(int p) {
int sum = 0;
while(p > 0) sum += tree[p], p -= lsb(p);
return sum;
}
};
signed main() {
cin.tie(0) -> sync_with_stdio(0);
int n;
cin >> n;
queue<int> que[2];
AIB aib;
aib.init(n);
for(int i = 1; i <= n; i++) {
char ch;
cin >> ch;
if(ch == 'B') que[0].emplace(i);
else que[1].emplace(i);
}
for(int i = 1; i <= n; i++) aib.upd(i, 1);
ll sum = 0;
for(int i = 1; i <= n; i++) {
char ch;
int P;
cin >> ch;
if(ch == 'B') P = que[1].front(), que[1].pop();
else P = que[0].front(), que[0].pop();
//cerr << aib.query(n) - aib.query(P);
sum += aib.query(n) - aib.query(P);
aib.upd(P, -1);
}
cout << sum << '\n';
}
/**
Istenem! Nu poate fi real.
-- Surse verificate
*/
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 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 |
1 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 |
1 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 |
1 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 |
- |