MohamDah, your code fails with small random tests too, so you can debug it. Here is an example:

[
  [ -3, 1 ],    [ 9, 16 ],
  [ -6, -4 ],   [ -7, 1 ],
  [ -13, -10 ], [ 20, 21 ],
  [ 5, 13 ],    [ 10, 15 ],
  [ -11, -6 ],  [ 8, 18 ]
]

Your code returns 29 instead of 28.

Same dude. I've spent more than 3 hours trying to get past that final one. The worst is that it doesn't even tell me why it's failing.

Why do I forget about regex?

Not a kata suggestion. See https://docs.codewars.com/training/troubleshooting#post-discourse.

They should include in the description:
"brackets must be closed in the order they were opened"
Otherwise, test case #4 " "[(])" => False" is valid

In the part where you reverse the words (for(int j=words[i].length();j>=0;j--)), the index j goes out of bounds. The correct range should be from words[i].length() - 1 down to 0.

You're appending characters to the word variable, but you're not pushing it to the cut_string vector correctly. The word is only added to cut_string when a space is encountered, but this doesn't properly handle the last word in the string if there's no trailing space.

OP solved it, closing

kata hint != kata suggestion

intersting kata, use Array's function , string => array => string