on java

1.Given a string str, return a string created from str, where each character has been replaced by the next one in alphabetical order. The method should be called NextAlphabetical.

2. Given a 1D array of integers A, return the minimum value in A. Method should be called Minimum.

3. Given a 1D array of integers A, return true if the difference between the minimum value in A and the maximum value in A is less than the size of the array, false otherwise. The method should be called TightArray.