1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
#include <bits/stdc++.h>

#define rep(a,b,c) for(auto a = (b); a != (c); a++)
#define repD(a,b,c) for(auto a = (b); a != (c); a--)
#define repIn(a, b) for(auto& a : (b))
#define repIn2(a, b, c) for(auto& [a, b] : (c))

constexpr bool dbg = 0;
#define DEBUG if constexpr(dbg)
#define DC DEBUG std::cerr
#define eol std::endl

#define int long long
#define ld long double
#define pb push_back

using namespace std;
#define rg ranges

int32_t main() {
    ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
    int n, k;
    cin >> n >> k;
    vector<int> v(n), v2(n), was(n);
    rep(i, 0, n) cin >> v[i];
    v2 = v;
    rep(_, 1, n) {
        pair<int, int> mx = {-1, -1};
        rep(i, 0, n) if(!was[i]) mx = max(mx, {v[i], i});
        auto [vj, j] = mx;
        rep(i, 0, n) v[i] = max(v[i], vj - k * abs(j - i));
        was[j] = 1;
    }
    DEBUG rep(i, 0, n) assert(v[i] >= v2[i]);
    int ans = 0;
    rep(i, 0, n) ans += v[i] - v2[i];
    cout << ans << '\n';
}