Clean up day 13 a little.

Very dirty solution day 13
2025-12-25 21:00:31 +01:00 · 2021-12-13 08:52:57 +01:00 · 2021-12-13 08:50:00 +01:00
4 changed files with 1082 additions and 5 deletions
--- a/2021/inputs/13.txt
+++ b/2021/inputs/13.txt
@@ -0,0 +1,894 @@
 899,112
 477,249
 462,60
 49,299
 1097,819
 890,74
 477,231
 1242,464
 57,641
 833,471
 1292,784
 1232,717
 898,227
 442,749
 893,116
 395,423
 1304,695
 211,186
 1097,243
 1004,46
 654,361
 1044,784
 745,284
 376,637
 634,737
 509,369
 242,395
 199,442
 397,170
 634,94
 954,15
 1019,219
 798,782
 340,262
 1299,598
 1133,23
 967,5
 291,675
 519,119
 97,698
 291,107
 301,592
 505,537
 1280,780
 340,632
 919,588
 733,884
 166,577
 530,840
 1197,187
 1004,605
 244,668
 38,368
 1241,170
 1161,199
 597,701
 594,140
 1161,691
 505,357
 666,381
 947,107
 1268,179
 984,585
 418,775
 805,471
 1074,455
 142,245
 284,403
 1064,557
 207,766
 485,759
 236,775
 38,309
 329,59
 1169,857
 791,775
 1310,809
 530,715
 571,401
 525,673
 1064,701
 304,110
 402,350
 1237,172
 646,287
 959,156
 62,320
 674,364
 959,738
 723,535
 177,423
 798,85
 497,859
 825,99
 473,593
 575,45
 505,215
 764,133
 109,684
 884,457
 356,879
 920,238
 310,233
 79,266
 177,663
 691,868
 1290,352
 714,745
 493,527
 1173,65
 1026,520
 284,473
 662,647
 557,522
 1190,667
 181,180
 1178,114
 990,3
 798,649
 428,224
 428,511
 254,567
 574,669
 468,672
 324,801
 1290,542
 120,702
 271,312
 145,817
 1082,187
 1014,493
 691,420
 718,544
 412,560
 420,368
 428,432
 326,585
 686,108
 1297,25
 1290,782
 689,893
 1046,798
 194,588
 423,873
 97,876
 748,634
 865,887
 296,493
 1046,350
 488,311
 1048,411
 344,152
 962,718
 410,893
 986,801
 527,274
 798,654
 736,107
 462,95
 999,826
 1119,595
 604,652
 261,124
 20,352
 581,50
 417,778
 820,260
 310,651
 95,21
 20,21
 629,32
 1133,471
 1082,885
 82,450
 1079,0
 798,334
 420,634
 1243,87
 290,262
 477,295
 226,511
 915,670
 364,632
 248,625
 1062,269
 331,324
 713,193
 739,65
 74,667
 1248,574
 903,490
 65,868
 1250,306
 149,695
 574,673
 246,787
 570,717
 1225,105
 214,36
 904,336
 991,726
 1054,661
 744,765
 324,353
 73,546
 667,150
 780,179
 1136,381
 920,14
 57,253
 825,404
 638,427
 170,297
 231,465
 792,140
 979,773
 669,8
 1216,10
 1020,262
 758,158
 879,516
 621,893
 1183,172
 370,25
 140,446
 1034,820
 301,289
 325,835
 167,794
 1293,304
 58,521
 108,504
 718,96
 621,393
 890,816
 977,180
 236,887
 1277,309
 197,53
 999,397
 1133,599
 619,26
 932,746
 842,149
 1236,765
 16,651
 1216,688
 1149,367
 743,819
 706,674
 1212,259
 130,623
 273,54
 284,25
 284,491
 485,411
 313,248
 79,406
 1046,96
 13,663
 35,710
 306,166
 560,206
 1168,245
 460,101
 363,362
 505,19
 1248,47
 264,432
 1280,767
 1031,100
 1158,869
 48,861
 334,653
 1135,822
 1175,595
 884,885
 512,85
 484,745
 900,449
 157,852
 497,266
 946,632
 217,236
 256,661
 248,558
 47,570
 1103,766
 1215,425
 842,672
 947,362
 996,710
 1033,75
 552,812
 62,798
 862,702
 756,803
 3,466
 934,677
 1252,521
 1220,103
 570,499
 997,438
 1245,677
 30,753
 900,673
 1119,593
 716,754
 264,350
 420,484
 1144,87
 6,695
 493,504
 669,231
 1051,695
 97,522
 97,565
 954,463
 674,595
 63,292
 961,409
 348,848
 166,359
 686,767
 192,575
 848,319
 925,477
 735,182
 326,107
 470,117
 1183,620
 370,822
 349,37
 957,78
 209,781
 30,464
 62,803
 94,884
 542,36
 1307,793
 398,681
 604,450
 376,329
 175,520
 495,820
 764,504
 768,858
 241,341
 502,869
 1,726
 252,675
 157,490
 672,427
 1059,355
 1151,820
 319,168
 1016,719
 726,302
 895,371
 527,620
 1151,436
 805,647
 540,705
 1153,547
 1304,199
 817,367
 88,126
 1074,439
 1289,140
 1096,702
 1243,359
 739,401
 448,702
 858,85
 810,291
 1120,754
 1190,702
 239,523
 805,215
 920,350
 1176,211
 853,221
 985,661
 428,670
 341,438
 566,129
 333,714
 853,124
 624,767
 1240,368
 641,250
 1236,227
 1218,484
 1303,840
 587,871
 408,892
 1004,838
 109,210
 716,140
 1093,658
 773,7
 654,309
 1049,677
 674,530
 318,831
 1118,767
 997,456
 740,717
 1238,791
 848,127
 541,259
 830,8
 363,219
 584,526
 672,651
 353,816
 457,322
 112,529
 1004,56
 161,390
 900,1
 169,135
 25,862
 584,220
 872,123
 893,778
 186,672
 341,194
 303,268
 992,383
 465,368
 13,25
 1168,240
 311,516
 713,701
 646,607
 1240,526
 510,558
 723,359
 842,558
 726,880
 979,757
 1202,257
 495,773
 70,686
 753,522
 94,688
 753,428
 273,532
 197,501
 485,722
 840,848
 420,816
 186,149
 698,403
 363,676
 1262,861
 512,112
 1201,658
 129,98
 1022,309
 1263,324
 569,660
 74,675
 80,409
 177,232
 455,4
 818,527
 480,397
 186,222
 1114,581
 783,620
 1201,236
 197,893
 1118,95
 489,728
 388,140
 604,242
 1216,240
 797,754
 756,539
 797,37
 1173,872
 622,623
 489,815
 117,143
 291,184
 863,128
 730,765
 73,722
 892,7
 488,535
 813,628
 940,822
 552,318
 273,840
 1086,289
 1280,464
 822,311
 149,295
 477,697
 391,588
 1237,348
 262,483
 6,199
 584,592
 485,539
 390,126
 490,738
 1170,373
 1140,297
 934,637
 396,436
 1233,385
 733,765
 947,219
 349,485
 490,746
 643,338
 1084,511
 979,122
 408,555
 820,290
 669,25
 1253,701
 813,72
 999,378
 1176,855
 1124,745
 132,780
 706,204
 581,157
 667,556
 562,410
 808,869
 428,383
 3,101
 996,632
 261,746
 577,10
 830,886
 489,838
 344,742
 1136,845
 398,661
 398,238
 1019,787
 142,649
 584,302
 438,771
 288,302
 1161,295
 92,634
 606,145
 970,632
 1034,74
 1079,894
 142,240
 1275,710
 820,746
 1173,22
 74,577
 855,890
 689,501
 497,347
 358,688
 636,364
 567,819
 1022,302
 758,736
 1253,253
 428,501
 821,815
 887,21
 1213,490
 764,705
 60,306
 1153,255
 1056,327
 601,168
 1099,634
 880,718
 1146,604
 1213,18
 1178,780
 822,535
 1161,471
 952,127
 1201,210
 688,623
 574,221
 890,634
 170,597
 157,42
 1084,393
 310,661
 666,8
 375,548
 597,193
 390,544
 65,677
 263,180
 621,449
 1165,714
 842,745
 582,473
 997,472
 1145,815
 25,32
 820,156
 612,520
 957,302
 770,705
 113,187
 1114,313
 825,411
 698,267
 813,347
 1236,667
 723,807
 169,815
 805,194
 1280,114
 1223,815
 820,820
 790,659
 850,101
 1250,588
 955,525
 676,782
 1113,221
 224,289
 1290,649
 284,421
 574,787
 1020,632
 1026,25
 961,530
 858,267
 1237,157
 1238,439
 952,206
 996,184
 1292,364
 969,707
 546,133
 619,555
 575,182
 584,880
 979,137
 30,268
 477,214
 797,857
 1039,582
 1144,359
 211,17
 790,235
 1180,623
 915,224
 477,471
 261,665
 833,295
 830,662
 601,138
 656,361
 922,688
 1262,145
 1231,406
 858,361
 616,816
 1290,270
 764,189
 320,689
 18,530
 813,266
 363,107
 577,436
 609,439
 560,464
 229,490
 480,886
 281,333
 202,267
 1078,10
 492,527
 929,362
 373,781
 381,586
 126,150
 246,109
 169,68
 508,691
 638,243
 741,234
 1081,404
 1290,245
 1034,298
 621,841
 821,728
 23,44
 1260,674
 1044,140
 217,628
 750,688
 1140,149
 552,736
 261,453
 192,95
 452,361
 1140,597
 726,368
 798,688
 519,147
 1082,707
 1294,19
 70,357
 840,693
 691,362
 1148,77
 311,68
 654,555
 90,710
 1049,770
 1019,184
 130,271
 403,707
 67,87
 837,593
 1213,404
 1294,518
 162,186
 893,330
 698,520
 87,75
 976,451
 157,266
 758,576
 719,154
 903,493
 822,583
 594,530
 70,144
 1153,628
 463,327
 1216,884
 654,533
 902,709
 714,597
 141,485
 634,112
 723,87
 833,231
 159,325
 977,714
 206,285
 853,572
 301,414
 1004,400
 750,884
 358,127
 1046,432
 520,235
 594,812
 801,873
 1169,37
 986,353
 1006,110
 1099,260
 915,695
 1062,784
 410,143
 1300,8
 1297,259
 348,737
 175,822
 348,157
 1037,54
 1014,849
 785,673
 518,866
 716,812
 418,119
 497,72
 1093,236
 1069,553
 566,765
 703,801
 1230,409
 1029,333
 1190,227
 94,206
 641,886
 1268,161
 1181,221
 417,116
 47,324
 1124,672
 870,140
 159,121
 440,226
 169,31
 428,462
 440,858
 395,672
 348,46
 236,632
 184,848
 735,712
 470,693
 243,782
 940,869
 154,603
 935,548
 1039,841
 490,143
 149,471
 920,880
 243,112
 706,652
 817,504
 465,884
 581,844
 914,884
 711,536
 90,343
 952,530
 1290,21
 135,595
 868,749
 1238,473
 898,667
 174,397
 1078,688
 990,689
 1272,368
 438,123
 400,262
 102,812
 1184,150
 691,666
 567,371
 982,107
 537,887
 800,110
 735,180
 32,623
 242,110
 632,334
 753,789
 411,65
 1290,737
 313,438
 900,751
 333,180
 426,457
 261,677
 440,140
 714,297
 527,172
 729,546
 673,142
 457,501
 1168,688
 1124,149
 664,383
 848,799
 480,381
 159,436
 867,821
 213,243
 378,148
 947,676
 72,473
 1133,645
 1150,653
 653,840
 912,233
 769,259
 1133,871
 913,724
 22,334
 fold along x=655
 fold along y=447
 fold along x=327
 fold along y=223
 fold along x=163
 fold along y=111
 fold along x=81
 fold along y=55
 fold along x=40
 fold along y=27
 fold along y=13
 fold along y=6
--- a/2021/src/common.rs
+++ b/2021/src/common.rs
@@ -53,7 +53,7 @@ impl<'a, I: FromStr> LineParser<'a, I> {
    }
 }
-impl<'a, I: FromStr> Iterator for LineParser<'a, I> {
+impl<I: FromStr> Iterator for LineParser<'_, I> {
    type Item = I;
    fn next(&mut self) -> Option<Self::Item> {
@@ -61,6 +61,15 @@ impl<'a, I: FromStr> Iterator for LineParser<'a, I> {
    }
 }
 impl<'a, I: FromStr> From<LineIter<'a>> for LineParser<'a, I> {
    fn from(iter: LineIter<'a>) -> Self {
        Self {
            iter,
            _data: PhantomData,
        }
    }
 }
 /// Return two arguments in their natural PartialOrd order
 pub fn ordered<O: PartialOrd>(a: O, b: O) -> (O, O) {
    if a < b {
--- a/2021/src/day13.rs
+++ b/2021/src/day13.rs
@@ -1,9 +1,162 @@
 use std::collections::HashSet;
 use std::io::Read;
 use std::str::FromStr;
-pub fn part1(_input: &mut dyn Read) -> String {
+use nom::branch::alt;
-    todo!()
+use nom::bytes::complete::tag;
 use nom::error::Error;
 use nom::sequence::tuple;
 use nom::Finish;
 use nom::IResult;
 use crate::common::LineIter;
 use crate::common::LineParser;
 type Coords = (u16, u16);
 enum Fold {
    X(u16),
    Y(u16),
 }
-pub fn part2(_input: &mut dyn Read) -> String {
+impl FromStr for Fold {
-    todo!()
+    type Err = Error<String>;
    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let (_, fold) = parse_fold(s)
            .finish()
            .map_err(|Error { input, code }| Error {
                input: input.to_string(),
                code,
            })?;
        Ok(fold)
    }
 }
 fn parse_coordinates(input: &str) -> IResult<&str, Coords> {
    use nom::character::complete::char;
    use nom::character::complete::u16;
    let (input, (x, _, y)) = tuple((u16, char(','), u16))(input)?;
    Ok((input, (x, y)))
 }
 fn parse_fold(input: &str) -> IResult<&str, Fold> {
    use nom::character::complete::char;
    use nom::character::complete::u16;
    let (input, (_, axis, _, coord)) = tuple((
        tag("fold along "),
        alt((char('x'), char('y'))),
        char('='),
        u16,
    ))(input)?;
    let fold = match axis {
        'x' => Fold::X(coord),
        'y' => Fold::Y(coord),
        _ => unreachable!("Should be filtered by nom"),
    };
    Ok((input, fold))
 }
 fn read_dots(reader: &mut LineIter<'_>) -> HashSet<Coords> {
    let mut dots = HashSet::new();
    while let Some(line) = reader.next() {
        if line.is_empty() {
            break;
        }
        let (_, coords) = parse_coordinates(line).unwrap();
        dots.insert(coords);
    }
    dots
 }
 fn apply_fold(dots: &mut HashSet<Coords>, fold: Fold, to_fold: &mut Vec<Coords>) {
    match fold {
        Fold::X(coord) => dots.retain(|&(x, y)| {
            if x < coord {
                true
            } else {
                to_fold.push((2 * coord - x, y));
                false
            }
        }),
        Fold::Y(coord) => dots.retain(|&(x, y)| {
            if y < coord {
                true
            } else {
                to_fold.push((x, 2 * coord - y));
                false
            }
        }),
    }
    dots.extend(to_fold.drain(..));
 }
 fn print_dots(dots: &HashSet<Coords>) -> String {
    let (x, y) = dots
        .iter()
        .fold((0, 0), |(xc, yc), &(xn, yn)| (xc.max(xn), yc.max(yn)));
    let mut buffer = String::with_capacity((x as usize + 1) * y as usize);
    for y in 0..=y {
        for x in 0..=x {
            if dots.contains(&(x, y)) {
                buffer.push('#');
            } else {
                buffer.push(' ');
            }
        }
        buffer.push('\n');
    }
    buffer.pop();
    buffer
 }
 pub fn part1(input: &mut dyn Read) -> String {
    let mut reader = LineIter::new(input);
    let mut dots = read_dots(&mut reader);
    let fold = reader.next().unwrap().parse().unwrap();
    apply_fold(&mut dots, fold, &mut Vec::new());
    dots.len().to_string()
 }
 pub fn part2(input: &mut dyn Read) -> String {
    let mut reader = LineIter::new(input);
    let mut dots = read_dots(&mut reader);
    let mut to_fold = Vec::new();
    LineParser::from(reader).for_each(|fold| apply_fold(&mut dots, fold, &mut to_fold));
    print_dots(&dots)
 }
 #[cfg(test)]
 mod tests {
    use super::*;
    use crate::test_implementation;
    const SAMPLE: &[u8] = include_bytes!("samples/13.txt");
    #[test]
    fn sample_part() {
        test_implementation(part1, SAMPLE, 17);
    }
 }
--- a/2021/src/samples/13.txt
+++ b/2021/src/samples/13.txt
@@ -0,0 +1,21 @@
 6,10
 0,14
 9,10
 0,3
 10,4
 4,11
 6,0
 6,12
 4,1
 0,13
 10,12
 3,4
 3,0
 8,4
 1,10
 2,14
 8,10
 9,0
 fold along y=7
 fold along x=5
Author	SHA1	Message	Date
Bert Peters	ffe8d27469	Clean up day 13 a little.	2021-12-13 08:52:57 +01:00
Bert Peters	d471f170b3	Very dirty solution day 13	2021-12-13 08:50:00 +01:00