function generateValidParentheses(n){
function generate(l,r,n,p){
var output=[];
if(r>=n){
output.push(p.join(''));
return output;
}
if(r<l){
p[l+r]=')';
output = output.concat(generate(l,r+1,n,p));
}
if(l<n){
p[l+r]='(';
output = output.concat(generate(l+1,r,n,p));
}
return output;
}
return generate(0,0,n,[]);
}
Problem Statement: Given n pairs of parentheses, generate set of all valid parentheses permutations
Solution: Given n pairs of parentheses this solution uses a simple logic that left parentheses can be place in the string as long number of left parentheses used so far is less than n, and a right parentheses can be place in the string as long as number of right parentheses used so far is less than the number of left parentheses used so far.