Given a string consisting of opening and closing parenthesis, find length of the longest valid parenthesis substring.

longest_valid_parentheses

//http://practice.geeksforgeeks.org/problems/longest-valid-parentheses/0
var seq = [1,0,1,0,1,1]
var counts = [];
var stack = [];
for(var i=seq.length-1;i>=0;i--){
	var val = seq[i];
	if(val){
		stack.push(val);
	}
	if(!val){
		if(stack.pop()){
			if(counts.length){
				counts[counts.length-1] +=2;
			}else{
				counts.push(2);
			}
		}else{
			counts.push(0);
		}
	}
}
console.log(counts);