@[JerryWayne7](/user/811743) 没必要
```cpp
#include<bits/stdc++.h>
using namespace std;
int main(){
int n,a[100005],ans=0;
cin>>n;
for(int i=1;i<=n;i++) cin>>a[i];
for(int i=1;i<=n;i++) if(a[i]>a[i-1]) ans+=a[i]-a[i-1];
cout<<ans;
return 0;
}
```
仅供参考
by xq_z @ 2024-01-31 12:03:42
@[xq_z](/user/611614) THX!
by JerryWayne7 @ 2024-01-31 15:54:15