package ScrambleString;
import java.util.HashMap;
import java.util.Map;
/**
* User: Danyang
* Date: 1/28/2015
* Time: 19:06
*
* Given a string s1, we may represent it as a binary tree by partitioning it to two non-empty substrings recursively.
Below is one possible representation of s1 = "great":
great
/ \
gr eat
/ \ / \
g r e at
/ \
a t
To scramble the string, we may choose any non-leaf node and swap its two children.
For example, if we choose the node "gr" and swap its two children, it produces a scrambled string "rgeat".
rgeat
/ \
rg eat
/ \ / \
r g e at
/ \
a t
We say that "rgeat" is a scrambled string of "great".
Similarly, if we continue to swap the children of nodes "eat" and "at", it produces a scrambled string "rgtae".
rgtae
/ \
rg tae
/ \ / \
r g ta e
/ \
t a
We say that "rgtae" is a scrambled string of "great".
Given two strings s1 and s2 of the same length, determine if s2 is a scrambled string of s1.
*/
public class Solution {
/**
* Algorithm: recursive
* treat as set of chars
* partition the string
*
* Notice:
* 1. prune, otherwise TLE
* @param s1
* @param s2
* @return
*/
public boolean isScramble(String s1, String s2) {
if(s1.equals(s2))
return true;
if(!relaxedEqual(s1, s2))
return false;
for(int l=1; l