New puzzle

[akalai]

def sat(inds: List[int]):
    return inds == sorted(inds) and "".join("enlightenment"[i] for i in inds) == "intelligent"

Please post your solutions to this puzzle in the comments using the following formatting:

<details><summary>Reveal solution</summary>
```python
def sol():
    return "world" # replace with your solution
```
</details>

[mlb2251]

Reveal solution

def sol():
   s = "stackringshrubs"
   start = -len(s)
   res = []
   for c in "substring":
     for i in range(start,len(s)):
       if s[i] == c:
         res.append(i)
         start = i
         break
   return res