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| #include <bits/stdc++.h>
using namespace std;
#define ri register
#define id(x) (lower_bound(b + 1, b + L + 1, x) - b)
#define rid(x) b[x]
#define lson(x) node[x].l
#define rson(x) node[x].r
#define node_id(x) node[x].node_id
#define sum(x) node[x].sum
typedef long long ll;
typedef pair<int, ll> pii;
const int INF = 0x3f3f3f3f;
const int MAXN = 50005;
const int MAXM = 50005;
int cnt_node = 0;
namespace MCMF {
struct Edge {
int u, v, val, cos, next;
} e[MAXM * 2];
int n, m, t = 1, Head[MAXN], v[MAXN], S, T;
deque<int> q;
ll d[MAXN], Delta;
inline void AddEdge(int x, int y, int v, int c) {
e[++t] = (Edge){ x, y, v, c, Head[x] }, Head[x] = t;
e[++t] = (Edge){ y, x, 0, -c, Head[y] }, Head[y] = t;
}
inline bool Relabel(void) {
memset(d, 0x3f, sizeof d);
memset(v, 0, sizeof v);
d[T] = 0, v[T] = 1, q.push_front(T);
while (!q.empty()) {
int x = q.front();
q.pop_front(), v[x] = 0;
if (q.size() > 1 && d[q.front()] > d[q.back()])
swap(q.front(), q.back());
for (int i = Head[x], y; i; i = e[i].next)
if (e[i ^ 1].val && d[y = e[i].v] > d[x] + e[i ^ 1].cos) {
d[y] = d[x] + e[i ^ 1].cos;
if (v[y])
continue;
v[y] = true, q.push_back(y);
if (q.size() > 1 && d[q.front()] > d[q.back()])
swap(q.front(), q.back());
}
}
return d[S] != d[0];
}
inline int Dinic(int x, int flow) {
if (!flow || x == T)
return flow;
int residue = flow;
v[x] = true;
for (int i = Head[x], y; i; i = e[i].next)
if (e[i].val && !v[y = e[i].v] && !e[i].cos) {
int k = Dinic(y, min(e[i].val, residue));
e[i].val -= k, e[i ^ 1].val += k;
if ((residue -= k) == 0)
break;
}
return flow - residue;
}
inline pii PrimalDual(void) {
int Maxflow = 0;
ll Mincost = 0;
while (Relabel()) {
for (int i = 2; i <= t; i++) e[i].cos += d[e[i].v] - d[e[i].u];
Delta += d[S];
int Flow = 0;
while (memset(v, 0x00, sizeof v), (Flow = Dinic(S, INF)))
Maxflow += Flow, Mincost += 1ll * Flow * Delta;
}
return pii(Maxflow, Mincost);
}
}
int n, w;
pair<ll, int> a[MAXN];
ll b[MAXN], c[MAXN];
int L;
int root0[MAXN], root1[MAXN];
int pos0[MAXN], pos1[MAXN];
struct Node {
int l, r, node_id, sum;
} node[MAXN * 22];
int cnt = 0;
void AddEdge(int u, int l, int r, int p, bool t) {
int mid = (l + r) >> 1;
int llen = mid - l + 1, rlen = r - mid;
int lsum = sum(lson(u)), rsum = sum(rson(u));
if (lson(u))
MCMF ::AddEdge(node_id(u), node_id(lson(u)), lsum, llen == 1 ? (t == 0 ? -c[l] : c[l]) : 0);
if (rson(u))
MCMF ::AddEdge(node_id(u), node_id(rson(u)), rsum, rlen == 1 ? (t == 0 ? -c[r] : c[r]) : 0);
}
void insert(int v, int& u, int l, int r, int p, bool t) {
u = ++cnt;
if (l == r) {
sum(u) = 1;
node_id(u) = l;
return;
}
node_id(u) = ++cnt_node;
int mid = (l + r) >> 1;
if (p <= mid)
insert(lson(v), lson(u), l, mid, p, t), rson(u) = rson(v);
else
insert(rson(v), rson(u), mid + 1, r, p, t), lson(u) = lson(v);
sum(u) = sum(lson(u)) + sum(rson(u));
AddEdge(u, l, r, p, t);
}
void query(int u, int l, int r, int ql, int qr, int cur, int num, bool t) {
if (u == 0)
return;
if (ql <= l && r <= qr) {
MCMF ::AddEdge(cur, node_id(u), sum(u), l == r ? abs(c[num] - c[l]) : (t == 0 ? c[num] : -c[num]));
return;
}
int mid = (l + r) >> 1;
if (ql <= mid)
query(lson(u), l, mid, ql, qr, cur, num, t);
if (mid < r)
query(rson(u), mid + 1, r, ql, qr, cur, num, t);
}
int main() {
scanf("%d%d", &n, &w);
for (int i = 1; i <= n; ++i) scanf("%lld", &a[i].first), b[i] = c[i] = a[i].first, a[i].second = i;
sort(b + 1, b + n + 1);
L = unique(b + 1, b + n + 1) - b - 1;
sort(a + 1, a + n + 1);
cnt_node = n;
root0[0] = ++cnt, node_id(root0[0]) = ++cnt_node;
for (int i = 1; i <= n; ++i) {
pos0[id(a[i].first)] = i;
insert(root0[i - 1], root0[i], 1, n, a[i].second, 0);
}
reverse(a + 1, a + n + 1);
root1[0] = ++cnt, node_id(root1[0]) = ++cnt_node;
for (int i = 1; i <= n; ++i) {
pos1[id(a[i].first)] = i;
insert(root1[i - 1], root1[i], 1, n, a[i].second, 1);
}
MCMF ::S = ++cnt_node, MCMF ::T = ++cnt_node;
for (int i = 1; i < n; ++i) {
query(root0[pos0[id(c[i])]], 1, n, i + 1, n, ++cnt_node, i, 0);
query(root1[pos1[id(c[i])]], 1, n, i + 1, n, cnt_node, i, 1);
MCMF ::AddEdge(MCMF ::S, cnt_node, 1, 0);
MCMF ::AddEdge(i, MCMF ::T, 1, 0);
MCMF ::AddEdge(MCMF ::S, i, 1, w);
}
MCMF ::AddEdge(MCMF ::S, ++cnt_node, 1, 0);
MCMF ::AddEdge(n, MCMF ::T, 1, 0);
MCMF ::AddEdge(MCMF ::S, n, 1, w);
pii ans = MCMF ::PrimalDual();
printf("%lld\n", ans.second);
return 0;
}
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