#include <iostream>#include <cstdio>#include <cstring>using namespace std;int dp[110000],p[11000],p_low[11000],p_up[11000];int max(int a,int b){ return a>b?a:b;}int min(int a,int b){ return a<b?a:b;}int abs(int n){ return n>0?n:-n;}int main(){ int n,i,j,l,d,t; scanf("%d%d",&n,&l); for (i=0; i<n; i++) { scanf("%d",p+i); } if (n == 1) { printf("0n"); return 0; } d=l/(n-1); p_low[0]=0; p_up[0]=0; p_low[n-1]=l; p_up[n-1]=l; for (i=1; i<n-1; i++) { p_low[i]=max(d*i,l-(d+1)*(n-i-1)); if (p_low[i] < 0) p_low[i]=0; p_up[i]=min((d+1)*i,l-d*(n-i-1)); if (p_up[i] > l) p_up[i]=l; } memset(dp,0x3f,sizeof(dp)); dp[0]=p[0]; for (i=1; i<n; i++) { for (j=p_up[i]; j>=p_low[i]; j--) { t=j-d; dp[j]=0x3f3f3f3f; if (t >= p_low[i-1] && t <= p_up[i-1]) dp[j]=min(dp[j],dp[t]+abs(j-p[i])); t--; if (t >= p_low[i-1] && t <= p_up[i-1]) dp[j]=min(dp[j],dp[t]+abs(j-p[i])); } } printf("%dn",dp[l]);}
