2018网易校园招聘 DP

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
using namespace std;
long long dp[2020][2020],n,a[2020];
int dfs(int x1,int x2){
if(dp[x1][x2]!=-1) return dp[x1][x2];
if(x1==n-1 ) return dp[x1][x2]=min(abs(a[x1]-a
),abs(a[x2]-a
));
dp[x1][x2]=min(dfs(x1+1,x2)+(x1==0?0:abs(a[x1+1]-a[x1])),dfs(x1+1,x1)+(x2==0?0:abs(a[x1+1]-a[x2])));
return dp[x1][x2];
}
int main(){
scanf("%d",&n);
memset(dp,-1,sizeof(dp));
for(int i=1;i<=n;i++)
scanf("%lld",&a[i]);
dfs(1,0);
printf("%lld\n",dp[1][0]);
}