String excercises

E01

Given two strings of the same length (passed as constant references), return the number of characters in corresponding positions in which they differ.

For example:

• "casa" differs from "cosa" in 1 position.
• "abc" differs from "cab" in all 3 positions
• "elefante" differents from "elefante" in 0 positions

Do not use any function from the string class except length (and [] to access the characters)

E02

Given two strings of the same length (passed as constant references), return true if one can be obtained from the other by swapping exactly two characters. For example,

• "cosa", "caso" would return true
• "abc" , "cba" would return true
• "xyz" , "xab" would return false
• "cotorra", "corotra" would return true
• "a", "b" would return false

Do not use any function from the string class except length (and [] to access the characters)

E03

A string is considered an abbreviation of a word if we can form the word by inserting zero o more letters at the beginning, end or between the characters of the abbreviation. For example:

• "gtr" is an abbreviation of "guitar"

• "bne" is an abbreviation of "trombone", "bone", "binder" and many other words

• "pai" is not abbreviation of "piano" because the piano contains p, a, i in another

• "pai" is an abbreviation of "paint", "polarity", "apartheid", and many others

Write a function bool abbreviation(const string &abrev, const string &word) that receives two strings and returns true if the first is an abbreviation of the second

Do not use any function from the string class except length (and [] to access the characters)