Minimum Add to Make Parentheses Valid - Leetcode 921 - Python

0:00 - Read the problem
0:30 - Drawing Explanation
5:34 - Coding Explanation

leetcode 921

#neetcode #leetcode #python

[kermatt]

Was confused by the problem description, came here to understand it and solved it. Thank you neetcode

[anshumansingh]

high key, watching your videos is so therapeutic

[nirmalgurjar]

Yesterday's problem was interesting than this, this seems easy after solving yday problem.

[amanaryan]

Always loved the way you explain the concept. Would be glad if you can upload a video on segment Tree and it's lazy propagation.

[MyLuck]

This problem already we did right in this month

[kewlvk]

Code can be simplified a bit
class Solution(object):
def minAddToMakeValid(self, s):
open_count = result = 0

for c in s:
if c == "(":
open_count+=1
elif open_count:
open_count-=1
else:
result+=1

return open_count+result

[vijayarun_]

using stack



class Solution {
public:
int minAddToMakeValid(string s) {
stack<char> st;
int cnt =0;
for(int i = 0;i<s.size();i++){
if(s[i] == '('){
st.push(s[i]);
}else if(!st.empty() && s[i] == ')'){
st.pop();
}else{
cnt++;
}
}
return cnt+st.size();
}
};

[advolv]

Love the videos man, gotta lock in for recruting this semester 😭
430. Flatten a Multilevel Doubly Linked List
if you can could you solve the above question?

[LankeshM-reop]

The problem description was more confusing than the solution. Actually the solution is preety much feels easy problem.

[abhimanyuambastha]

Guy just called more than half of his viewers NOOB lol

[chaitanyayeole]

I did this by myself, my code may not be the best but I think it was using the yesterday questions logic.

class Solution:
def minAddToMakeValid(self, s: str) -> int:
open_, close = 0, 0
adds = 0

for c in s:
if c == '(':
open_ += 1
else:
close += 1

if close > open_:
adds += 1
close -= 1

if open_ > close:
adds += open_ - close

return adds