模型:每次选连续区间将区间内所有数减去一,使得所有数都为0的最少操作次数

#include<bits/stdc++.h>
using namespace std;
const int N = 1e5;
int a[N],b[N];
int main()
{
    int n;
    cin>>n;
    for (int i = 1; i <= n; i ++ )
    {
      cin>>a[i];
      b[i]=a[i]-a[i-1];
      //cout<<b[i]<<" ";
    }
    int sr=0,st=0;
    for (int i = 1; i <= n; i ++ )
    {
      if(b[i]<0) st+=b[i];
      else sr+=b[i];
    }
    int res=min(abs(st),sr)+sr-abs(st);
    cout<<res;
}