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#![ feature(test) ]
extern crate test ;
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use aoc2020 ::common ::* ;
use std ::collections ::HashSet ;
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fn main ( ) {
let input = parse_input ( & read_input ( ) ) ;
println! ( " Part 1: {} " , part1 ( & input ) ) ;
println! ( " Part 2: {} " , part2 ( & input ) ) ;
}
fn read_input ( ) -> String {
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read_file ( 6 )
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}
fn parse_input ( raw : & str ) -> Vec < Vec < HashSet < char > > > {
raw . split ( " \n \n " )
. map ( | group | group . lines ( ) . map ( | l | l . chars ( ) . collect ( ) ) . collect ( ) )
. collect ( )
}
fn part1 ( answers : & [ Vec < HashSet < char > > ] ) -> usize {
answers . iter ( ) . map ( | v | v . iter ( ) . fold ( HashSet ::new ( ) , | a , b | & a | b ) . len ( ) ) . sum ( )
}
fn part2 ( answers : & [ Vec < HashSet < char > > ] ) -> usize {
answers . iter ( ) . map ( | v | v . iter ( ) . fold ( v [ 0 ] . clone ( ) , | a , b | & a & b ) . len ( ) ) . sum ( )
}
#[ cfg(test) ]
mod tests {
use super ::* ;
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use aoc2020 ::* ;
use paste ::paste ;
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use test ::black_box ;
const TEST_INPUT : & str = " abc
a
b
c
ab
ac
a
a
a
a
b " ;
const TEST_INPUT_2 : & str = " fsl
fsg
fs
fts
sf
a
bdfghjkl
hdcl
cdlh
hdcl
hldc
ldhc " ;
fn part2_help ( answers : & [ Vec < HashSet < char > > ] ) -> Vec < usize > {
answers . iter ( ) . map ( | v | v . iter ( ) . fold ( v [ 0 ] . clone ( ) , | a , b | & a & b ) . len ( ) ) . collect ( )
}
#[ test ]
fn part2_test ( ) {
assert_eq! ( part2_help ( & parse_input ( TEST_INPUT_2 ) ) , vec! [ 2 , 0 , 4 ] ) ;
assert_eq! ( part2 ( & parse_input ( TEST_INPUT ) ) , 6 ) ;
}
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bench_input! ( len = = 490 ) ;
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test! ( part1 ( ) = = 11 ) ;
bench! ( part1 ( ) = = 6735 ) ;
bench! ( part2 ( ) = = 3221 ) ;
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}