1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
|
use std::fs;
use std::process;
fn main() {
let raw = fs::read_to_string("input.txt").unwrap_or_else(|err| {
println!("Failed to open file. {}", err);
process::exit(1);
} );
let nums : Vec<i32> = raw.lines()
.map(|x| x.parse().unwrap())
.collect();
let res : Vec<i32> = nums.iter()
.map(|&x| nums.iter().map(move |&y| (x, y)))
.flatten()
.filter(|(x, y)| x+y == 2020)
.map(|(x, y)| x*y)
.collect();
println!("x+y = 2020, x*y = {}", res.first().unwrap());
let nx = nums.clone().into_iter();
let ny = nums.clone().into_iter();
let nz = nums.clone().into_iter();
let cube = nx.flat_map(|x| {
ny.clone().flat_map({
let nz = &nz;
move |y| nz.clone().map(move |z| (x, y, z))
})
});
let res : Vec<i32> = cube
.filter(|(x, y, z)| x+y+z == 2020)
.map(|(x, y, z)| x*y*z)
.collect();
println!("x+y+z = 2020, x*y*z = {}", res.first().unwrap());
}
|
