Exercise 22.3 (Pattern Matching) Write a program that prompts the user to enter two strings and tests whether the second string is a substring of the first string. Suppose the neighboring characters in the string are distinct. (Dont use the indexOf method in the String class.) Analyze the time complexity of your algorithm. Your algorithm needs to be at least O(n) time. Here is a sample run of the program:

Enter a string s1: Welcome to Java Enter a string s2: come matched at index 3