#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
template <typename T>
struct FenwickTree {
size_t n;
vector<T> bit;
FenwickTree(size_t n): n(n), bit(n, 0) {};
FenwickTree(vector<T> & init): n((int) init.size()), bit((int) init.size()) {
copy(init.begin(), init.end(), bit.begin());
for(int i = 1; i <= n; i++) {
if(i + (i & -i) <= n) {
bit[i + (i & -i) - 1] += bit[i - 1];
}
}
}
T qry(int k) {
T ret = 0;
for(k++; k > 0; k -= k & -k) {
ret += bit[k - 1];
}
return ret;
}
T qry(int l, int r) {
return qry(r) - qry(l - 1);
}
void upd(int k, T x) {
for(k++; k <= n; k += k & -k) {
bit[k - 1] += x;
}
}
};
ll count_swaps(vector<int> S) {
int n = S.size();
ll ans = 0;
FenwickTree<ll> ft(n);
vector<int> lefts;
vector<vector<int>> rights(n / 2);
for(int i = 0; i < n; i++) {
ft.upd(i, 1);
if(S[i] < 0) {
lefts.push_back(i);
} else {
rights[S[i] - 1].push_back(i);
}
}
for(int i = 0; i < n / 2; i++) {
reverse(rights[i].begin(), rights[i].end());
}
for(int i = 0; i < n / 2; i++) {
ft.upd(lefts[i], -1); ans += ft.qry(lefts[i]);
int pos = -S[lefts[i]] - 1, right_back = rights[pos].back(); rights[pos].pop_back();
ft.upd(right_back, -1); ans += ft.qry(right_back);
}
return ans;
}
Compilation message
shoes.cpp: In instantiation of 'void FenwickTree<T>::upd(int, T) [with T = long long int]':
shoes.cpp:43:20: required from here
shoes.cpp:30:20: warning: comparison of integer expressions of different signedness: 'int' and 'size_t' {aka 'long unsigned int'} [-Wsign-compare]
30 | for(k++; k <= n; k += k & -k) {
| ~~^~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
1 ms |
304 KB |
Output is correct |
7 |
Correct |
0 ms |
212 KB |
Output is correct |
8 |
Correct |
0 ms |
212 KB |
Output is correct |
9 |
Correct |
1 ms |
296 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
11 |
Correct |
1 ms |
212 KB |
Output is correct |
12 |
Correct |
1 ms |
212 KB |
Output is correct |
13 |
Correct |
0 ms |
212 KB |
Output is correct |
14 |
Incorrect |
1 ms |
300 KB |
Output isn't correct |
15 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
0 ms |
212 KB |
Output is correct |
7 |
Correct |
1 ms |
212 KB |
Output is correct |
8 |
Correct |
1 ms |
212 KB |
Output is correct |
9 |
Correct |
1 ms |
296 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
11 |
Correct |
1 ms |
212 KB |
Output is correct |
12 |
Correct |
1 ms |
212 KB |
Output is correct |
13 |
Correct |
1 ms |
212 KB |
Output is correct |
14 |
Correct |
0 ms |
212 KB |
Output is correct |
15 |
Correct |
0 ms |
212 KB |
Output is correct |
16 |
Correct |
1 ms |
304 KB |
Output is correct |
17 |
Correct |
0 ms |
212 KB |
Output is correct |
18 |
Correct |
1 ms |
340 KB |
Output is correct |
19 |
Correct |
1 ms |
340 KB |
Output is correct |
20 |
Correct |
4 ms |
1108 KB |
Output is correct |
21 |
Correct |
3 ms |
1108 KB |
Output is correct |
22 |
Correct |
34 ms |
7892 KB |
Output is correct |
23 |
Correct |
31 ms |
7976 KB |
Output is correct |
24 |
Correct |
34 ms |
7980 KB |
Output is correct |
25 |
Correct |
28 ms |
7976 KB |
Output is correct |
26 |
Correct |
32 ms |
7968 KB |
Output is correct |
27 |
Correct |
30 ms |
7860 KB |
Output is correct |
28 |
Correct |
30 ms |
8112 KB |
Output is correct |
29 |
Correct |
31 ms |
8100 KB |
Output is correct |
30 |
Correct |
32 ms |
8132 KB |
Output is correct |
31 |
Correct |
34 ms |
7876 KB |
Output is correct |
32 |
Correct |
29 ms |
8096 KB |
Output is correct |
33 |
Correct |
31 ms |
7972 KB |
Output is correct |
34 |
Correct |
34 ms |
8132 KB |
Output is correct |
35 |
Correct |
1 ms |
212 KB |
Output is correct |
36 |
Correct |
1 ms |
212 KB |
Output is correct |
37 |
Correct |
31 ms |
8112 KB |
Output is correct |
38 |
Correct |
35 ms |
8096 KB |
Output is correct |
39 |
Correct |
31 ms |
8096 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
1 ms |
212 KB |
Output is correct |
5 |
Correct |
43 ms |
10544 KB |
Output is correct |
6 |
Correct |
43 ms |
8100 KB |
Output is correct |
7 |
Correct |
41 ms |
10436 KB |
Output is correct |
8 |
Correct |
33 ms |
8104 KB |
Output is correct |
9 |
Correct |
40 ms |
10520 KB |
Output is correct |
10 |
Correct |
43 ms |
8980 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
1 ms |
304 KB |
Output is correct |
7 |
Correct |
0 ms |
212 KB |
Output is correct |
8 |
Correct |
0 ms |
212 KB |
Output is correct |
9 |
Correct |
1 ms |
296 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
11 |
Correct |
1 ms |
212 KB |
Output is correct |
12 |
Correct |
1 ms |
212 KB |
Output is correct |
13 |
Correct |
0 ms |
212 KB |
Output is correct |
14 |
Incorrect |
1 ms |
300 KB |
Output isn't correct |
15 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
1 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
0 ms |
212 KB |
Output is correct |
5 |
Correct |
1 ms |
212 KB |
Output is correct |
6 |
Correct |
1 ms |
304 KB |
Output is correct |
7 |
Correct |
0 ms |
212 KB |
Output is correct |
8 |
Correct |
0 ms |
212 KB |
Output is correct |
9 |
Correct |
1 ms |
296 KB |
Output is correct |
10 |
Correct |
1 ms |
212 KB |
Output is correct |
11 |
Correct |
1 ms |
212 KB |
Output is correct |
12 |
Correct |
1 ms |
212 KB |
Output is correct |
13 |
Correct |
0 ms |
212 KB |
Output is correct |
14 |
Incorrect |
1 ms |
300 KB |
Output isn't correct |
15 |
Halted |
0 ms |
0 KB |
- |