#include <bits/stdc++.h>
using namespace std;
#define fast ios::sync_with_stdio(0);cin.tie(0);
#define s second
#define f first
typedef long long ll;
const ll MOD = 1e9 + 7;
const ll LOGN = 20;
const ll MAXN = 1e5 + 5;
vector<int> occ[26];
int fen[MAXN], n;
int query(int k) {
int res = 0;
while (k >= 1) {
res += fen[k];
k -= (k&-k);
}
return res;
}
void update(int k, int val) {
while (k <= n) {
fen[k] += val;
k += (k&-k);
}
}
int main() {
fast
string s;
cin >> n >> s;
s = "#" + s;
for (int i = 0; i < 26; i++)
occ[i] = vector<int>();
for (int i = 1; i <= n; i++)
occ[s[i]-'a'].push_back(i);
for (int i = 0; i < 26; i++)
reverse(occ[i].begin(), occ[i].end());
vector<int> v;
for (int i = n+1; i <= 2*n; i++) {
v.push_back(occ[s[i]-'a'].back());
occ[s[i]-'a'].pop_back();
}
int ans = 0;
int cnt = 0;
for (auto u : v) {
ans += cnt - query(u);
update(u, 1);
cnt++;
}
cout << ans << "\n";
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
600 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
600 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
600 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Execution timed out |
1068 ms |
348 KB |
Time limit exceeded |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
1 ms |
600 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |