/**
* Author: Nicholas Winschel
* Created: 04.04.2023 20:21:56
**/
#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using db=long double;
using pi = pair<int,int>;
using vpi = vector<pi>;
int dp[1001][1001],last[1001][1001];
template<class T> void cm(T &a, const T &b) {
if (b < a) a = b;
}
int main(){
cin.tie(0)->sync_with_stdio(0); // initialize fast I/O
int n; cin >> n;
vpi vals;
for (int i = 0; i < n; i++) {
int c; cin >> c; vals.emplace_back(-c,i);
}
sort(vals.begin(),vals.end());
vector<int> p(n);
for (int i = 0; i < n; i++) {
p[vals[i].second]=i;
}
p.push_back(n);
vals.emplace_back(-1,n);
for (int i = 0; i < n; i++) dp[n][i]=1e9;
dp[n][n]=0;
for (int i = n-1; i >= 0; i--) {
int v = 1;
for (int j = 0; j < vals[i].second; j++) if (p[j]<i) v++;
int v2 = 1;
for (int h = 0; h <= n; h++) {
if (p[h] < i) v2++;
dp[i][h] = dp[i+1][h]+v+v2;
last[i][h] = h;
}
int o = 0;
for (int k = vals[i].second+1; k <= n; k++) {
int t = dp[i+1][k]+o;
if (t < dp[i][vals[i].second]) {
dp[i][vals[i].second] = t;
last[i][vals[i].second] = k;
}
o += max(0, i-p[k]);
}
}
pi best{1e9, -1};
for (int i = 0; i <= n; i++) cm(best, {dp[0][i],i});
assert(best.second>=0);
bitset<1001> b;
for (int i = 0; i < n; i++) {
if (best.second == vals[i].second) b[i] = true;
best.second = last[i][best.second];
}
vpi m;
for (int i = n-1; i >= 0; i--) {
if (b[i]) continue;
int f = find(p.begin(), p.end(), i)-p.begin();
int t = find(p.begin(), p.end(), i+1)-p.begin();
m.emplace_back(f+1,t+1);
p.erase(p.begin()+f);
p.insert(find(p.begin(),p.end(), i+1),i);
}
cout << m.size() << "\n";
for (auto &&p : m) {
cout << p.first << " " << p.second << "\n";
}
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
328 KB |
Integer 8 violates the range [1, 7] |
2 |
Incorrect |
1 ms |
340 KB |
not sorted |
3 |
Incorrect |
1 ms |
340 KB |
not sorted |
4 |
Incorrect |
1 ms |
724 KB |
Integer 51 violates the range [1, 50] |
5 |
Incorrect |
1 ms |
1108 KB |
Integer 101 violates the range [1, 100] |
6 |
Incorrect |
1 ms |
1876 KB |
Integer 201 violates the range [1, 200] |
7 |
Incorrect |
3 ms |
4180 KB |
Integer 501 violates the range [1, 500] |
8 |
Incorrect |
5 ms |
6612 KB |
Integer 801 violates the range [1, 800] |
9 |
Correct |
7 ms |
8204 KB |
Output is correct |
10 |
Incorrect |
7 ms |
8148 KB |
Integer 1001 violates the range [1, 1000] |