Hi, I have implemented my algorithm in python, however it has the time limitted error. I think I am using DP to solve the problem but why does this error come out?

```
class Solution:
def wordBreak(self, s, dict):
length=len(s)+1
res=[]
result=[]
for i in range(length):
res.append(False)
result.append([])
res[0]=True
for i in range(length-1):
if s[0:i] in dict:
result[i].append(s[0:i])
for i in range(length-1):
for j in range(i+1):
if res[j]==True and s[j:(i+1)] in dict:
res[i+1]=True
for it in result[j]:
result[i+1].append(it+" "+s[j:(i+1)])
if res[length-1]:
return result[-1]
else:
return []
```