Q18 Generate Parentheses - LeetCode 22
Wed Mar 22 2023 18:42:50 GMT+0000 (Coordinated Universal Time)
Saved by
@Ayush_dabas07
class Solution {
public List<String> generateParenthesis(int n) {
/* you can find how many total no. of brackets will be generated
through catalan number
TC for interview purposes - O(n * 2^2n)
*/
backtrack("" , 0 , 0 , n);
return res;
}
public List<String> res = new ArrayList<>();
//open -> open brackets , clost brackets
public void backtrack(String sb , int open , int close , int n){
//base condition
if(sb.length() == 2*n){
res.add(sb);
return;
}
//always start with open bracket
if(open < n)
backtrack(sb + "(", open + 1 , close , n);
//close brackets should always be lesser than open,make recursion
//tree to understand this better
if(close < open)
backtrack(sb + ")",open ,close+1 , n);
}
}
content_copyCOPY
https://leetcode.com/problems/generate-parentheses/
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