Word Bigram Counts X41372


Statement
 

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A word bigram is a combination of two words appearing consecutively in a text. For instance the text "tea for you and tea for me" contains 5 different bigrams: tea+for (occurring twice), for+you, you+and, and+tea, for+me.

Write a program that reads a text given as input, counts the bigrams it contains, and produces a list with the total count of bigrams starting with each word, and the relative frequency of the second word. The list must contain only those words that happen more than once as first word in a bigram.

Note that the last word in the text is not the first word in any bigram, so it is not counted in the number of bigrams starting with that word.

For instance, in the sentence "tea for you and tea for me and for him also tea", we obtain the following counts:

  • Word and happens 2 times as a bigram first word. Once (50%) followed by tea and once (50%) followed by for.
  • Word for happens 3 times as a bigram first word. Once (33%) followed by you, once (33%) followed by me, and once (33%) followed by him.
  • Word tea happens 2 times as a bigram first word. Both times (i.e. 100%) is followed by for. Word tea also happens a third time (last word in the text) but since that occurrence is not first word of any bigram, it is not counted as such.
  • Words you, me, also, and him happen only once as bigram first word, so they are not included in the final list.

So, the expected output would be: 

and 2 : for 0.5 tea 0.5
for 3 : him 0.333 me 0.333 you 0.333
tea 2 : for 1.0

Input

The input is a text. It may consist of several lines.

Output

The output is a list where for each word appearing more than once, the number of occurrences is provided, followed by the words occurring right after, along with their relative frequencies.

Relative frequencies are rounded to 3 decimal places. Use round(x,3) to round a float value x to 3 decimals.
The word list is ordered alphabetically.
The list of second words seen after each word is also ordered alphabetically.

Follow the output format shown in the examples.

Public test cases

  • Input

    tea for you and tea for me and for him also tea

    Output

    and 2 : for 0.5 tea 0.5
for 3 : him 0.333 me 0.333 you 0.333
tea 2 : for 1.0

  • Input

    how much wood would a woodchuck chuck
if a woodchuck could chuck wood
he would chuck he would as much as he could
and chuck as much wood as a woodchuck 
would if a woodchuck could chuck wood

    Output

    a 4 : woodchuck 1.0
as 4 : a 0.25 he 0.25 much 0.5
chuck 5 : as 0.2 he 0.2 if 0.2 wood 0.4
could 3 : and 0.333 chuck 0.667
he 3 : could 0.333 would 0.667
if 2 : a 1.0
much 3 : as 0.333 wood 0.667
wood 3 : as 0.333 he 0.333 would 0.333
woodchuck 4 : chuck 0.25 could 0.5 would 0.25
would 4 : a 0.25 as 0.25 chuck 0.25 if 0.25

  • Input

    Write a program that reads a text given as input 
counts the bigrams it contains 
and produces a list with the total count of 
bigrams starting with each word and the 
relative frequency of the second word

    Output

    a 3 : list 0.333 program 0.333 text 0.333
and 2 : produces 0.5 the 0.5
bigrams 2 : it 0.5 starting 0.5
of 2 : bigrams 0.5 the 0.5
the 4 : bigrams 0.25 relative 0.25 second 0.25 total 0.25
with 2 : each 0.5 the 0.5
    • Information
    Author
    ProAl1 professors
    Language
    English
    Official solutions
    Python
    User solutions
    Python