11use super :: day:: { Day } ;
2- use std:: fmt;
32
43
54// CrabSubmarine
@@ -28,25 +27,41 @@ impl CrabSubmarine {
2827}
2928 result
3029}
30+
31+ fn compute_distance2 ( & self ) ->u32 {
32+ let result: u32 ;
33+ if self . start_pos >self . dest_pos {
34+ result =( 0 ..=self . start_pos -self . dest_pos ) . into_iter ( ) . fold ( 0 , |acc, x| acc+x)
35+ }
36+ else {
37+ result =( 0 ..=self . dest_pos -self . start_pos ) . into_iter ( ) . fold ( 0 , |acc, x| acc+x)
38+ }
39+ result
40+ }
3141}
3242
3343
3444
3545pub struct Day07 { }
3646
47+ impl Day07 {
48+ fn parse_input ( input : & str ) ->Vec < u32 > {
49+ input. lines ( )
50+ . next ( )
51+ . unwrap ( )
52+ . split ( ',' )
53+ . map ( |x| x. parse ( ) . unwrap ( ) )
54+ . collect :: < Vec < u32 > > ( )
55+ }
56+ }
57+
3758impl Day for Day07 {
3859fn day_number ( & self ) ->& str {
3960"07"
4061}
4162
4263fn part_1 ( & self ) ->String {
43- let mut input: Vec < u32 > =self . load_input ( )
44- . lines ( )
45- . next ( )
46- . unwrap ( )
47- . split ( ',' )
48- . map ( |x| x. parse ( ) . unwrap ( ) )
49- . collect :: < Vec < u32 > > ( ) ;
64+ let mut input: Vec < u32 > =Day07 :: parse_input ( & self . load_input ( ) ) ;
5065 input. sort ( ) ;
5166// Compute median
5267let med;
@@ -67,30 +82,22 @@ impl Day for Day07 {
6782}
6883
6984fn part_2 ( & self ) ->String {
70- let mut input: Vec < u32 > =self . load_input ( )
71- . lines ( )
72- . next ( )
73- . unwrap ( )
74- . split ( ',' )
75- . map ( |x| x. parse ( ) . unwrap ( ) )
76- . collect :: < Vec < u32 > > ( ) ;
85+ let mut input: Vec < u32 > =Day07 :: parse_input ( & self . load_input ( ) ) ;
7786 input. sort ( ) ;
78- // Compute median
79- let med;
80- let len = input. len ( ) ;
81- if len %2 !=0 {
82- med = input[ len /2 ] ;
83- }
84- else {
85- med =( input[ ( len -1 ) /2 ] + input[ len /2 ] ) /2 ;
86- }
87- let fuel: u32 = input. iter ( )
88- . map ( |& x|CrabSubmarine :: new ( x, med) )
89- . collect :: < Vec < _ > > ( )
90- . into_iter ( )
91- . map ( |cs| cs. compute_distance ( ) )
92- . sum ( ) ;
93- println ! ( "Fuel: {}" , fuel) ;
87+ // Run through the full range
88+ let max = input[ input. len ( ) -1 ] ;
89+ let fuel: u32 =( 0 ..=max) . into_iter ( )
90+ . map ( |v|
91+ {
92+ input. iter ( )
93+ . map ( |& x|CrabSubmarine :: new ( x, v) )
94+ . collect :: < Vec < _ > > ( )
95+ . into_iter ( )
96+ . map ( |cs| cs. compute_distance2 ( ) )
97+ . sum ( )
98+ } )
99+ . min ( )
100+ . unwrap ( ) ;
94101 fuel. to_string ( )
95102}
96103}
