Write a program that prompts the user to enter two strings andtest whether the second string is a substring of the first string(don’t use the indexOf method in the String class). Analyze the time complexity of your algorithm. For example, if you enter Mississippi and sip the program willprint that they were matched at index 6. Now write an O(n) time program that will perform the same task.Provide the code of both programs and highlight the changesmade. Need answer in JavaFX . . .