题解

动态规划
参考代码：

#include <bits/stdc++.h>
using namespace std;

int main(){
    long long n,k,a[100010],dp[100010] = {0};
    cin >> n >> k;
    for (long long i = 1;i <= n;i++){
        cin >> a[i];
    }
    memset(dp,0x3f,sizeof(dp));
    dp[1] = 0;
    for (long long i = 2;i <= n;i++){
        for (long long j = 1;j <= k;j++){
            if(i - j > 0){
                dp[i] = min(dp[i],dp[i - j] + abs(a[i-j] - a[i]));
            }
        }

    }
    cout << dp[n];
    return 0;
}