uva - 1442(cav 递推类 ，思路)

#include <set>
#include <vector>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
typedef long long LL;

const int maxn = 1000100;
int L[maxn],R[maxn];
int n,p[maxn],s[maxn];
int main()
{
    int T;
    scanf("%d",&T);
    while(T--){
         scanf("%d",&n);
         for(int i=1;i<=n;i++){
            scanf("%d",&p[i]);
         }
         for(int i=1;i<=n;i++){
            scanf("%d",&s[i]);
         }
         int level = s[1];
         for(int i=1;i<=n;i++){
             if(level<p[i]) level=p[i];
             if(level>s[i]) level=s[i];
             L[i] = level;
            // cout<<i<<" "<<level<<endl;
         }
         level = s
;
         for(int i=n;i>=1;i--){
             if(level<p[i]) level=p[i];
             if(level>s[i]) level=s[i];
             R[i] = level;
         }
         int res=0;
         for(int i=1;i<=n;i++){
             //cout<<min(L[i],R[i])<<endl;
             res+=min(L[i],R[i])-p[i];
         }
         printf("%d\n",res);
    }
    return 0;
}