#include <iostream>
#include <deque>
#include <set>
#include <cassert>
using namespace std;
const int INF = 1e9;
struct segTree{
int l, r, mid;
int val = 0, lz = 0;
segTree *lc, *rc;
segTree() = default;
segTree(int _l, int _r): l(_l), r(_r){
mid = (l + r) / 2;
if (l == r - 1) return;
lc = new segTree(l, mid);
rc = new segTree(mid, r);
}
int real_val(){
return val + lz;
}
void push(){
if (lz > 0){
lc->lz += lz;
rc->lz += lz;
lz = 0;
}
}
void pull(){
val = min(lc->real_val(), rc->real_val());
}
void update(int ll, int rr, int u){
if (ll <= l && rr >= r){
lz = u;
return;
}
push();
if (ll < mid)
lc->update(ll, rr, u);
if (mid < rr)
rc->update(ll, rr, u);
pull();
}
int query(int ll, int rr){
if (ll <= l && rr >= r){
return real_val();
}
push();
int ret = INF;
if (ll < mid)
ret = min(ret, lc->query(ll, rr));
if (mid < rr)
ret = min(ret, rc->query(ll, rr));
pull();
return ret;
}
};
int main(){
cin.tie(0)->sync_with_stdio(0);
int n, m; cin >> n >> m;
int a[n + 1]{};
for (int i = 1; i <= n; i++){
cin >> a[i];
}
int dp[n + 1][m + 1]{};
fill_n(&dp[0][0], sizeof(dp) / sizeof(int), INF);
deque<int> dq;
a[0] = INF;
dp[0][0] = 0;
dq.push_back(0);
segTree st[m];
for (int i = 0; i < m; i++){
st[i] = segTree(0, n + 1);
if (i > 0) st[i].update(0, 1, INF);
}
for (int i = 1; i <= n; i++){
// for (int j = 1; j <= m; j++){
// int cur = a[i];
// for (int k = i - 1; k >= 0; k--){
// dp[i][j] = min(dp[i][j], dp[k][j - 1] + cur);
// cur = max(cur, a[k]);
// }
// }
while (dq.size() && a[dq.back()] < a[i]){
int k = dq.back();
dq.pop_back();
for (int j = 1; j <= m; j++){
// assert(st[j - 1].find(dp[dq.back()][j - 1] + a[k]) != st[j - 1].end());
// st[j - 1].erase(st[j - 1].find(dp[dq.back()][j - 1] + a[k]));
st[j - 1].update(dq.back() + 1, k, a[i] - a[k]);
}
}
for (int j = 1; j <= m; j++){
dp[i][j] = st[j - 1].query(0, i) + a[i];
st[j - 1].update(i, i + 1, dp[i][j - 1]);
}
dq.push_back(i);
}
cout << dp[n][m] << '\n';
return 0;
}
# |
Verdict |
Execution time |
Memory |
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 |
- |
# |
Verdict |
Execution time |
Memory |
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 |
- |
# |
Verdict |
Execution time |
Memory |
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 |
- |
# |
Verdict |
Execution time |
Memory |
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 |
- |