90分#10WA

#include<bits/stdc++.h>
using namespace std;
int n,s,h[10009],H[10009],ans;
int main(){
    cin>>n;
    for(int i=1;i<=n;i++) cin>>h[i],H[i]=h[i];
    s=max_element(h+1,h+n+1)-h;
    for(int x=1;x<=5000;x++){
        int l=s,r=s;
        while(l>0&&H[l-1]<=H[l]) l--;
        while(r<=n&&H[r+1]<=H[r]) r++;
        if(l==0&&r==n+1) break;
        int tmp;
        if(l!=0){
            tmp=H[l];
            while(H[l]==tmp) H[l++]++;
        }
        if(r!=n+1){
            tmp=H[r];
            while(H[r]==tmp) H[r--]++;
        }
    }
    for(int i=1;i<=n;i++) ans+=H[i]-h[i];
    cout<<ans<<endl;
    return 0;
}