nove.dev
retroactive, to derust my rust
fix day7 part2
+48
-83
+16
Cargo.lock
+16
Cargo.lock
···
15
name = "aoc2024"
16
version = "0.1.0"
17
dependencies = [
18
+
"itertools",
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"regex",
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+
]
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+
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+
[[package]]
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+
name = "either"
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+
version = "1.15.0"
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+
source = "registry+https://github.com/rust-lang/crates.io-index"
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+
checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
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+
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+
[[package]]
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+
name = "itertools"
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+
version = "0.14.0"
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+
source = "registry+https://github.com/rust-lang/crates.io-index"
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+
checksum = "2b192c782037fadd9cfa75548310488aabdbf3d2da73885b31bd0abd03351285"
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+
dependencies = [
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+
"either",
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]
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[[package]]
+1
Cargo.toml
+1
Cargo.toml
+25
-78
src/day7.rs
+25
-78
src/day7.rs
···
1
pub fn day7_part1(input: &str) -> String {
2
let input = parse(input);
3
let sum: u64 = input
···
18
sum.to_string()
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}
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-
fn possible_with_concatenation(res: u64, operands: &[u64]) -> bool {
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let operator_count = operands.len() - 1;
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-
let possibilities = 0..(3u64.pow(operator_count as u32));
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-
for possibility in possibilities {
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-
if evaluate_with_concatenation(possibility, operands) == res {
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-
return true;
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-
}
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-
}
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-
dbg!(res);
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false
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}
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-
fn evaluate_with_concatenation(mut bitpattern: u64, operands: &[u64]) -> u64 {
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-
// dbg!(bitpattern, operands);
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-
let selected_option = bitpattern % 3;
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-
let mut result = if selected_option == 0 {
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-
operands[0] + operands[1]
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-
} else if selected_option == 1 {
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-
operands[0] * operands[1]
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-
} else {
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concatenate(operands[0], operands[1])
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-
};
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-
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-
let mut debug_operators = vec![];
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-
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-
for operator in 2..operands.len() {
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-
bitpattern /= 3;
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-
let selected_option = bitpattern % 3;
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-
result = if selected_option == 0 {
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-
result + operands[operator]
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-
} else if selected_option == 1 {
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-
result * operands[operator]
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-
} else {
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-
concatenate(result, operands[operator])
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-
};
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-
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-
debug_operators.push(if selected_option == 0 {
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-
'+'
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-
} else if selected_option == 1 {
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-
'*'
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-
} else {
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'|'
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-
});
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}
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-
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-
// dbg!(result, bitpattern, debug_operators);
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-
result
69
}
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fn concatenate(left: u64, right: u64) -> u64 {
72
-
let decimal_places_shift = (right as f64).log10().ceil() as u32;
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left * 10u64.pow(decimal_places_shift) + right
74
}
75
···
78
assert_eq!(concatenate(15, 6), 156)
79
}
80
81
-
fn possible(res: u64, operands: &[u64]) -> bool {
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-
// dbg!(res, operands);
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-
let operator_count = operands.len() - 1;
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-
let possibilities = 0..(2u64.pow(operator_count as u32));
85
-
for possibility in possibilities {
86
-
if evaluate(possibility, operands) == res {
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-
return true;
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-
}
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-
}
90
-
91
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false
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-
}
93
-
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-
fn evaluate(bitpattern: u64, operands: &[u64]) -> u64 {
95
-
// dbg!(bitpattern, operands);
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-
let mut result = if bitpattern & 0b1 == 0 {
97
-
operands[0] + operands[1]
98
-
} else {
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-
operands[0] * operands[1]
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-
};
101
-
102
-
for operator in 2..operands.len() {
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-
let multiply = bitpattern & (0b1 << (operator - 1)) != 0;
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-
if multiply {
105
-
result *= operands[operator];
106
-
} else {
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-
result += operands[operator];
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-
}
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-
}
110
-
111
-
// dbg!(result);
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-
result
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-
}
114
-
115
#[derive(Copy, Clone, Eq, PartialEq, Debug)]
116
enum Operator {
117
Times,
118
Plus,
119
}
120
121
fn parse(input: &str) -> Vec<(u64, Vec<u64>)> {
···
1
+
use itertools::Itertools;
2
+
3
pub fn day7_part1(input: &str) -> String {
4
let input = parse(input);
5
let sum: u64 = input
···
20
sum.to_string()
21
}
22
23
+
fn possible(result: u64, operands: &[u64]) -> bool {
24
let operator_count = operands.len() - 1;
25
+
(0..operator_count)
26
+
.map(|_| [Operator::Plus, Operator::Times])
27
+
.multi_cartesian_product()
28
+
.any(|operators| check(result, operands, operators.as_slice()))
29
}
30
31
+
fn possible_with_concatenation(result: u64, operands: &[u64]) -> bool {
32
+
let operator_count = operands.len() - 1;
33
+
(0..operator_count)
34
+
.map(|_| [Operator::Plus, Operator::Times, Operator::Concatenate])
35
+
.multi_cartesian_product()
36
+
.any(|operators| check(result, operands, operators.as_slice()))
37
+
}
38
39
+
fn check(result: u64, operands: &[u64], operators: &[Operator]) -> bool {
40
+
let mut accumulator = operands[0];
41
+
for (operator, operand) in operators.iter().zip(&operands[1..]) {
42
+
match operator {
43
+
Operator::Times => accumulator *= operand,
44
+
Operator::Plus => accumulator += operand,
45
+
Operator::Concatenate => accumulator = concatenate(accumulator, *operand),
46
+
}
47
}
48
+
result == accumulator
49
}
50
51
fn concatenate(left: u64, right: u64) -> u64 {
52
+
let decimal_places_shift = right.ilog10() + 1;
53
left * 10u64.pow(decimal_places_shift) + right
54
}
55
···
58
assert_eq!(concatenate(15, 6), 156)
59
}
60
61
#[derive(Copy, Clone, Eq, PartialEq, Debug)]
62
enum Operator {
63
Times,
64
Plus,
65
+
Concatenate,
66
}
67
68
fn parse(input: &str) -> Vec<(u64, Vec<u64>)> {
+6
-5
src/lib.rs
+6
-5
src/lib.rs
···
356
assert_eq!(result, "3598800864292");
357
}
358
359
-
// #[ignore]
360
#[test]
361
fn day7_part2_test() {
362
-
// let simple_result = day7::day7_part2(include_str!("../input/day7_custom.test.txt"));
363
-
// assert_eq!(simple_result, (12345 + 12034050 + 15 + 120).to_string());
364
365
-
// let test_result = day7::day7_part2(include_str!("../input/day7.test.txt"));
366
-
// assert_eq!(test_result, "11387");
367
let result = day7::day7_part2(include_str!("../input/day7.txt"));
368
let parsed_result: u64 = result.parse::<u64>().unwrap();
369
assert!(parsed_result > 318_910_516_761_637, "{parsed_result} was too low");
370
}
371
372
#[test]
···
356
assert_eq!(result, "3598800864292");
357
}
358
359
+
#[ignore]
360
#[test]
361
fn day7_part2_test() {
362
+
let simple_result = day7::day7_part2(include_str!("../input/day7_custom.test.txt"));
363
+
assert_eq!(simple_result, (12345 + 12034050 + 15 + 120).to_string());
364
365
+
let test_result = day7::day7_part2(include_str!("../input/day7.test.txt"));
366
+
assert_eq!(test_result, "11387");
367
let result = day7::day7_part2(include_str!("../input/day7.txt"));
368
let parsed_result: u64 = result.parse::<u64>().unwrap();
369
assert!(parsed_result > 318_910_516_761_637, "{parsed_result} was too low");
370
+
assert_eq!(parsed_result, 340_362_529_351_427);
371
}
372
373
#[test]