Adding readme file

Author: bugsweeper

97-InterleavingString/README.md

@@ -0,0 +1,48 @@
+Given strings s1, s2, and s3, find whether s3 is formed by an interleaving of s1 and s2.
+
+An interleaving of two strings s and t is a configuration where s and t are divided into n and m substrings respectively, such that:
+
+
+	s = s1 + s2 + ... + sn
+	t = t1 + t2 + ... + tm
+	|n - m| <= 1
+	The interleaving is s1 + t1 + s2 + t2 + s3 + t3 + ... or t1 + s1 + t2 + s2 + t3 + s3 + ...
+
+
+Note: a + b is the concatenation of strings a and b.
+
+ 
+Example 1:
+
+Input: s1 = "aabcc", s2 = "dbbca", s3 = "aadbbcbcac"
+Output: true
+Explanation: One way to obtain s3 is:
+Split s1 into s1 = "aa" + "bc" + "c", and s2 into s2 = "dbbc" + "a".
+Interleaving the two splits, we get "aa" + "dbbc" + "bc" + "a" + "c" = "aadbbcbcac".
+Since s3 can be obtained by interleaving s1 and s2, we return true.
+
+
+Example 2:
+
+Input: s1 = "aabcc", s2 = "dbbca", s3 = "aadbbbaccc"
+Output: false
+Explanation: Notice how it is impossible to interleave s2 with any other string to obtain s3.
+
+
+Example 3:
+
+Input: s1 = "", s2 = "", s3 = ""
+Output: true
+
+
+ 
+Constraints:
+
+
+	0 <= s1.length, s2.length <= 100
+	0 <= s3.length <= 200
+	s1, s2, and s3 consist of lowercase English letters.
+
+
+ 
+Follow up: Could you solve it using only O(s2.length) additional memory space?