HDU 5805 NanoApe Loves Sequence(ST 表 or 预处理)

#include<cstdio>
#include<algorithm>
#include<iostream>
#include<cstring>
#include<string>
#include<cmath>
#include<map>
#include<set>
#include<cstdlib>
#include<vector>
using namespace std;
#define cl(a,b) memset(a,b,sizeof(a))
#define LL long long
#define pb push_back
#define gcd __gcd

#define For(i,j,k) for(int i=(j);i<k;i++)
#define lowbit(i) (i&(-i))
#define _(x) printf("%d\n",x)

const int maxn = 1e6+200;
const int inf  = 1 << 28;

LL mx[maxn][30],mi[maxn][30];

LL a[maxn];
LL b[maxn];
void initRmq(int n){
for(int j=1;j<20;j++){
for(int i=0;i+(1<<j)-1<n;i++){
mx[i][j]=max(mx[i][j-1],mx[i+(1<<(j-1))][j-1]);
mi[i][j]=min(mi[i][j-1],mi[i+(1<<(j-1))][j-1]);
}
}
}
LL query(int x,int y){
if(x>y)return 0;
int k=log(y-x+1)/log(2.0);
LL mxx=max(mx[x][k],mx[y-(1<<k)+1][k]);
LL mii=min(mi[x][k],mi[y-(1<<k)+1][k]);
return max(abs(mxx),abs(mii));
}

int main() {
int T;
scanf("%d",&T);
int n;
while(T--) {
scanf("%d",&n);
for(int i=1;i<=n;i++){
scanf("%lld",&a[i]);
}
a[0]=a[1];a[n+1]=a
;n++;
int k=0;

for(int i=1;i<=n;i++,k++){
b[k]=a[i]-a[i-1];
mx[k][0]=mi[k][0]=b[k];
}
initRmq(k);
LL ans = query(2,k-1);

for(int i=1;i+1<k;i++){
LL t = max(abs(b[i+1]+b[i]),max(query(0,i-1),query(i+2,k-1)));
ans+=t;
}
printf("%lld\n",ans);

}
return 0;
}

#include<cstdio>
#include<algorithm>
#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<map>
#include<string>
#include<set>
#include<cstdlib>
using namespace std;
#define cl(a,b) memset(a,b,sizeof(a))
#define LL long long
#define pb push_back

#define For(i,j,k) for(int i=(j);i<k;i++)
#define lowbit(i) (i&(-i))
#define _(x) printf("%d\n",x)

const int maxn = 1e6+200;
const int inf  = 1 << 28;

LL a[maxn];
LL mxl[maxn],mxr[maxn];
int main(){
int T;scanf("%d",&T);
while(T--){
int n;scanf("%d",&n);
for(int i=1;i<=n;i++){
scanf("%lld",&a[i]);
mxl[i]=mxr[i]=0;
}
a[0]=a[1];

mxl[0]=0;
for(int i=1;i<=n;i++){
mxl[i]=max(mxl[i-1],abs(a[i]-a[i-1]));
}

mxr
=0;
for(int i=n-1;i>=1;i--){
mxr[i]=max(mxr[i+1],abs(a[i+1]-a[i]));
}

/*for(int i=1;i<=n;i++){
printf("%lld ",mxl[i]);
}puts("");
for(int i=1;i<=n;i++){
printf("%lld ",mxr[i]);
}
puts("");
*/

LL ans = 0;
for(int i=1;i<=n;i++){
if(i==1)ans+=mxr[i+1];
else if(i==n)ans+=mxl[i-1];
else ans+=max(abs(a[i+1]-a[i-1]),max(mxl[i-1],mxr[i+1]));
}
printf("%lld\n",ans);

}
return 0;
}