#include <bits/stdc++.h>
using namespace std;
using lint = long long;
using pi = array<lint, 2>;
#define sz(v) ((int)(v).size())
#define all(v) (v).begin(), (v).end()
const int MAXN = 2005;
struct bit {
int tree[MAXN];
void add(int x, int v) {
for (int i = x + 2; i < MAXN; i += i & -i)
tree[i] += v;
}
int query(int x) {
int ret = 0;
for (int i = x + 2; i; i -= i & -i)
ret += tree[i];
return ret;
}
} bit;
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n;
cin >> n;
vector<pi> a(n);
for (int i = 0; i < n; i++) {
cin >> a[i][0];
if (i % 2 == 1)
a[i][0] *= -1;
a[i][1] = i;
}
sort(all(a), [&](const pi &a, const pi &b) { return pi{abs(a[0]), a[1]} < pi{abs(b[0]), b[1]}; });
lint dp[2] = {0, lint(1e18)};
for (int i = 0; i < n; i++)
bit.add(i, 1);
for (int i = n - 1; i >= 0;) {
int j = i;
while (j >= 0 && abs(a[i][0]) == abs(a[j][0])) {
bit.add(a[j][1], -1);
j--;
}
if (abs(a[i][0]) == 0)
break;
vector<array<lint, 3>> values[2];
for (int k = j + 1; k <= i; k++) {
int L = bit.query(a[k][1]);
int R = j + 1 - L;
if (a[k][0] > 0)
values[0].push_back({L, R, (int)a[k][1]});
else
values[1].push_back({L, R, (int)a[k][1]});
}
for (int i = 0; i < 2; i++) {
for (int j = 1; j < sz(values[i]); j++) {
values[i][j][0] += values[i][j - 1][0];
}
for (int j = sz(values[i]) - 2; j >= 0; j--) {
values[i][j][1] += values[i][j + 1][1];
}
}
lint nxt[2] = {lint(1e18), lint(1e18)};
for (int j = 0; j < 2; j++) {
int LS = (j + 1) % 2;
int RS = (j + i) % 2;
int len = sz(values[0]) + sz(values[1]);
for (int k = 0; k <= len; k++) {
int pl[2] = {};
int pr[2] = {sz(values[0]), sz(values[1])};
vector<int> seq, seqR;
for (int l = 0; l < k; l++) {
int pos = (LS + l) % 2;
if (pl[pos] < sz(values[pos]))
seq.push_back(values[pos][pl[pos]][2]);
pl[pos]++;
}
for (int l = 0; l < len - k; l++) {
int pos = (RS + l) % 2;
pr[pos]--;
if (pr[pos] >= 0)
seqR.push_back(values[pos][pr[pos]][2]);
}
reverse(all(seqR));
for (auto &x : seqR)
seq.push_back(x);
if (pl[0] == pr[0] && pl[1] == pr[1]) {
lint cost = 0;
for (int i = 0; i < sz(seq); i++) {
bit.add(seq[i], +1);
cost += i + 1 - bit.query(seq[i]);
}
for (int i = 0; i < sz(seq); i++) {
bit.add(seq[i], -1);
}
for (int i = 0; i < 2; i++) {
if (pl[i])
cost += values[i][pl[i] - 1][0];
if (pl[i] < sz(values[i]))
cost += values[i][pl[i]][1];
}
nxt[j ^ (k % 2)] = min(nxt[j ^ (k % 2)], dp[j] + cost);
}
}
}
dp[0] = nxt[0];
dp[1] = nxt[1];
i = j;
// cout << dp[0] << " " << dp[1] << endl;
}
lint ans = min(dp[0], dp[1]);
if (ans > 1e12)
ans = -1;
cout << ans << "\n";
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
75 ms |
432 KB |
Output is correct |
5 |
Correct |
74 ms |
416 KB |
Output is correct |
6 |
Correct |
124 ms |
340 KB |
Output is correct |
7 |
Correct |
22 ms |
440 KB |
Output is correct |
8 |
Correct |
124 ms |
424 KB |
Output is correct |
9 |
Correct |
89 ms |
420 KB |
Output is correct |
10 |
Correct |
81 ms |
340 KB |
Output is correct |
11 |
Correct |
82 ms |
340 KB |
Output is correct |
12 |
Correct |
82 ms |
420 KB |
Output is correct |
13 |
Correct |
53 ms |
416 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
75 ms |
432 KB |
Output is correct |
5 |
Correct |
74 ms |
416 KB |
Output is correct |
6 |
Correct |
124 ms |
340 KB |
Output is correct |
7 |
Correct |
22 ms |
440 KB |
Output is correct |
8 |
Correct |
124 ms |
424 KB |
Output is correct |
9 |
Correct |
89 ms |
420 KB |
Output is correct |
10 |
Correct |
81 ms |
340 KB |
Output is correct |
11 |
Correct |
82 ms |
340 KB |
Output is correct |
12 |
Correct |
82 ms |
420 KB |
Output is correct |
13 |
Correct |
53 ms |
416 KB |
Output is correct |
14 |
Correct |
1 ms |
212 KB |
Output is correct |
15 |
Runtime error |
48 ms |
16844 KB |
Execution killed with signal 11 |
16 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
75 ms |
432 KB |
Output is correct |
5 |
Correct |
74 ms |
416 KB |
Output is correct |
6 |
Correct |
124 ms |
340 KB |
Output is correct |
7 |
Correct |
22 ms |
440 KB |
Output is correct |
8 |
Correct |
124 ms |
424 KB |
Output is correct |
9 |
Correct |
89 ms |
420 KB |
Output is correct |
10 |
Correct |
81 ms |
340 KB |
Output is correct |
11 |
Correct |
82 ms |
340 KB |
Output is correct |
12 |
Correct |
82 ms |
420 KB |
Output is correct |
13 |
Correct |
53 ms |
416 KB |
Output is correct |
14 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
15 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
75 ms |
432 KB |
Output is correct |
5 |
Correct |
74 ms |
416 KB |
Output is correct |
6 |
Correct |
124 ms |
340 KB |
Output is correct |
7 |
Correct |
22 ms |
440 KB |
Output is correct |
8 |
Correct |
124 ms |
424 KB |
Output is correct |
9 |
Correct |
89 ms |
420 KB |
Output is correct |
10 |
Correct |
81 ms |
340 KB |
Output is correct |
11 |
Correct |
82 ms |
340 KB |
Output is correct |
12 |
Correct |
82 ms |
420 KB |
Output is correct |
13 |
Correct |
53 ms |
416 KB |
Output is correct |
14 |
Correct |
1 ms |
212 KB |
Output is correct |
15 |
Runtime error |
48 ms |
16844 KB |
Execution killed with signal 11 |
16 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
75 ms |
432 KB |
Output is correct |
5 |
Correct |
74 ms |
416 KB |
Output is correct |
6 |
Correct |
124 ms |
340 KB |
Output is correct |
7 |
Correct |
22 ms |
440 KB |
Output is correct |
8 |
Correct |
124 ms |
424 KB |
Output is correct |
9 |
Correct |
89 ms |
420 KB |
Output is correct |
10 |
Correct |
81 ms |
340 KB |
Output is correct |
11 |
Correct |
82 ms |
340 KB |
Output is correct |
12 |
Correct |
82 ms |
420 KB |
Output is correct |
13 |
Correct |
53 ms |
416 KB |
Output is correct |
14 |
Incorrect |
0 ms |
212 KB |
Output isn't correct |
15 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
212 KB |
Output is correct |
2 |
Correct |
0 ms |
212 KB |
Output is correct |
3 |
Correct |
1 ms |
212 KB |
Output is correct |
4 |
Correct |
75 ms |
432 KB |
Output is correct |
5 |
Correct |
74 ms |
416 KB |
Output is correct |
6 |
Correct |
124 ms |
340 KB |
Output is correct |
7 |
Correct |
22 ms |
440 KB |
Output is correct |
8 |
Correct |
124 ms |
424 KB |
Output is correct |
9 |
Correct |
89 ms |
420 KB |
Output is correct |
10 |
Correct |
81 ms |
340 KB |
Output is correct |
11 |
Correct |
82 ms |
340 KB |
Output is correct |
12 |
Correct |
82 ms |
420 KB |
Output is correct |
13 |
Correct |
53 ms |
416 KB |
Output is correct |
14 |
Correct |
1 ms |
212 KB |
Output is correct |
15 |
Runtime error |
48 ms |
16844 KB |
Execution killed with signal 11 |
16 |
Halted |
0 ms |
0 KB |
- |