(CountingLetters) Modify the program of Fig. 2 to count the number of occurrences of each...

(CountingLetters) Modify the program of Fig. 2 to count the number of occurrences of each letter rather than of each word. For example, the string "HELLO THERE" contains two Hs, three Es, two L s, one O, one T and one R. Display the results.

Fig. 2 Program counts the number of occurrences of each word in a String.