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
39
40
41
42
#include <cstdlib>
#include <vector>
#include <iostream>
using namespace std;

int main() {
    int n, k; cin >> n >> k;
    vector<int> a(n);
    for (int i = 0; i < n; i++) cin >> a[i];

    int res = 0;
    for (int i = 1; i < n; i++) {
        int d = abs(a[i] - a[i - 1]);
        if (d > k) {
            res += d - k;
            if (a[i] < a[i - 1]) a[i] += d - k;
            else a[i - 1] += d - k;
        }
    }
    for (int i = n - 1; i > 0; i--) {
        int d = abs(a[i] - a[i - 1]);
        if (d > k) {
            res += d - k;
            if (a[i] < a[i - 1]) a[i] += d - k;
            else a[i - 1] += d - k;
        }
    }
    // for (int i = 0; i < n; i++) cout << a[i] << ' ';
    // cout << '\n';

    cout << res << '\n';
    return 0;
}
/*

4 2
7 3 0 2

6 2
0 3 4 8 2 1

*/