package problems.medium;
import problems.utils.TreeNode;
import java.util.Stack;
/**
* Created by sherxon on 3/11/17.
*/
public class ConstructBinaryTreefromString {
public static void main(String[] args) {
System.out.println(str2tree("4"));
}
static public TreeNode str2tree(String s) {
if (s == null || s.length() == 0) return null;
if (s.indexOf('(') == -1) {
return new TreeNode(Integer.parseInt(s));
}
int r = Integer.parseInt(s.substring(0, s.indexOf('(', 0)));
TreeNode root = new TreeNode(r);
Stack<TreeNode> stack = new Stack<>();
stack.push(root);
for (int i = 1; i < s.length() - 1; i++) {
char c = s.charAt(i);
if (c == '(') {
int left = s.indexOf(')', i + 1);
int right = s.indexOf('(', i + 1);
int min = 0;
if (left == -1) min = right;
else if (right == -1) min = left;
else min = Math.min(left, right);
r = Integer.parseInt(s.substring(i + 1, min));
if (stack.peek().left == null) {
stack.peek().left = new TreeNode(r);
stack.push(stack.peek().left);
} else {
stack.peek().right = new TreeNode(r);
stack.push(stack.peek().right);
}
} else if (c == ')') {
stack.pop();
}
}
return root;
}
}