In C language!!!

Problem 2 (50 points): Entering text using a phone keypad is problematic, because there are only 10 digits for 26 letters. As a result, each of the digit keys (other than 0 and 1, which could not be part of telephone exchange prefixes until about thirty years ago) is mapped to several letters, as shown in the following diagram: 2 3 DEF 4 5 6 MNO 7 8 9 0 Some cell phones use a "multi-tap" user interface, in which you tap the 2 key once for a, twice for b and three times for c, which can get tedious. A streamlined alternative is to use a predictive strategy in which the cell phone guesses which of the possible letter you intended, based on the sequence so far and its possible completions. For example, if you type the digit sequence 72, there are 12 possibilities: pa, pb, pc, qa, qb, qc, ra, rb rc, sa, sb, and sc. Only four of these-pa, ra, sa, and sc-seem promising because they are prefixes of common English words like party, radio, sandwich, and scanner. The others can be ignored because there are no common words that begin with those sequences of letters. If the user enters 9956, there are 144 (4 x 4 x 3 x 3) possible letter sequences, but you can be assured the user meant xylo since that is the only sequence that is a prefix of any English words. Problem 2 (50 points): Entering text using a phone keypad is problematic, because there are only 10 digits for 26 letters. As a result, each of the digit keys (other than 0 and 1, which could not be part of telephone exchange prefixes until about thirty years ago) is mapped to several letters, as shown in the following diagram: 2 3 DEF 4 5 6 MNO 7 8 9 0 Some cell phones use a "multi-tap" user interface, in which you tap the 2 key once for a, twice for b and three times for c, which can get tedious. A streamlined alternative is to use a predictive strategy in which the cell phone guesses which of the possible letter you intended, based on the sequence so far and its possible completions. For example, if you type the digit sequence 72, there are 12 possibilities: pa, pb, pc, qa, qb, qc, ra, rb rc, sa, sb, and sc. Only four of these-pa, ra, sa, and sc-seem promising because they are prefixes of common English words like party, radio, sandwich, and scanner. The others can be ignored because there are no common words that begin with those sequences of letters. If the user enters 9956, there are 144 (4 x 4 x 3 x 3) possible letter sequences, but you can be assured the user meant xylo since that is the only sequence that is a prefix of any English words