Calculating cumulative sum and percent of total for columns grouped by row - awk

Question

I have a very large table of values that is formatted like this:
apple 1 1
apple 2 1
apple 3 1
apple 4 1
banana 25 4
banana 35 10
banana 36 10
banana 37 10
Column 1 has many different fruit, with varying numbers of rows for each fruit.
I would like to calculate the cumulative sum of column 3 for each type of fruit in column 1, and the cumulative percentage of the total at each row, and add these as new columns. So the desired output would be this:
apple 1 1 1 25.00
apple 2 1 2 50.00
apple 3 1 3 75.00
apple 4 1 4 100.00
banana 25 4 4 11.76
banana 35 10 14 41.18
banana 36 10 24 70.59
banana 37 10 34 100.00
I can get part way there with awk, but I am struggling with how to get the cumulative sum to reset at each new fruit. Here is my horrendous awk attempt for your viewing pleasure:
#!/bin/bash
awk '{cumsum += $3; $3 = cumsum} 1' fruitfile > cumsum.tmp
total=$(awk '{total=total+$3}END{print total}' fruitfile)
awk -v total=$total '{ printf ("%s\t%s\t%s\t%.5f\n", $1, $2, $3, ($3/total)*100)}' cumsum.tmp > cumsum.txt
rm cumsum.tmp

Answer 1

Could you please try following, written and tested with shown samples.
awk '
FNR==NR{
a[$1]+=$NF
next
}
{
sum[$1]+=($NF/a[$1])*100
print $0,++b[$1],sum[$1]
}
' Input_file Input_file |
column -t
Output for shown samples will be as follows.
apple 1 1 1 25
apple 2 1 2 50
apple 3 1 3 75
apple 4 1 4 100
banana 25 4 1 11.7647
banana 35 10 2 41.1765
banana 36 10 3 70.5882
banana 37 10 4 100
Explanation: Adding detailed explanation for above.
awk ' ##Starting awk program from here.
FNR==NR{ ##Checking condition FNR==NR which will be TRUE when first time Input_file is being read.
a[$1]+=$NF ##Creating array a with index $1 and keep adding its last field value to it.
next ##next will skip all further statements from here.
}
{
sum[$1]+=($NF/a[$1])*100 ##Creating sum with index 1st field and keep adding its value to it, each value will have last field/value of a[$1] and multiplying it with 100.
print $0,++b[$1],sum[$1] ##Printing current line, array b with 1st field with increasing value of 1 and sum with index of 1st field.
}
' Input_file Input_file | ##Mentioning Input_file name here.
column -t ##Sending awk output to column command for better look.