3 files changed, 716 insertions, 0 deletions
diff --git a/2021/day4/Cargo.toml b/2021/day4/Cargo.toml
new file mode 100644
index 0000000..8842130
--- /dev/null
+++ b/2021/day4/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "day4"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/2021/day4/input.txt b/2021/day4/input.txt
new file mode 100644
index 0000000..4c28ac7
--- /dev/null
+++ b/2021/day4/input.txt
@@ -0,0 +1,601 @@
+76,69,38,62,33,48,81,2,64,21,80,90,29,99,37,15,93,46,75,0,89,56,58,40,92,47,8,6,54,96,12,66,83,4,70,19,17,5,50,52,45,51,18,27,49,71,28,86,74,77,11,20,84,72,23,31,16,78,91,65,87,79,73,94,24,68,63,9,88,82,30,42,60,13,67,85,44,59,7,53,22,1,26,41,61,55,43,39,3,35,25,34,57,10,14,32,97,95,36,98
+
+17 45 62 28 73
+39 12  0 52  5
+87 48 50 85 44
+66 57 78 94  3
+91 37 69 16  1
+
+ 1 67  4 58 13
+25 54 34 63 87
+59 70 66 72 71
+33 17  8 20 85
+69 46 50 41 88
+
+47 63 80 15 90
+24  1 40 94 13
+56 62 74 81 95
+43 88 37 99 22
+57 52 33 84 49
+
+33 58 54 28 10
+ 7 82 97 66 92
+95 77  5 86 84
+85 91 94 21 69
+23 12 13 98 46
+
+ 1 63 58 23  0
+67 14 45 42 32
+48 64 83 10 13
+74 16  3 79 46
+44 52 95 25  6
+
+93 47  5 96 28
+88 76 70  0 72
+77  1 36 54  9
+14 17 75 64 15
+79 66 61 78 26
+
+23 75 96 71 76
+63 59 39 65 36
+95 21 67 41 74
+ 9 97  4  2 49
+32 17 81  0 56
+
+77 53 30 94  5
+ 4 42 87 25 24
+52 15 68  9 45
+56 89 98 47 34
+99 32 27 78 46
+
+75 70 99 65 41
+87  6 11 88  1
+ 4 42 64 98 78
+63 50 69 79 39
+67 46 17 97 26
+
+26 73  6 79 47
+67 51 64 16 60
+ 8  1 61 76 39
+13 57 48 65 46
+63 83  4 92 71
+
+97 93 21 88 80
+58 42 53 95 90
+49 29 30 26 22
+66 51 75  8 13
+ 5 39 19  4 96
+
+77 16 33  1  6
+54 91 60 56 88
+ 4 59 24 79 22
+36 49 17 97 27
+67 99 92 62 86
+
+78 18 59 74 54
+79 68 23 51 85
+47 42 92 58 12
+30 97 19 26 15
+ 1 62 94 65 70
+
+ 6 91 56 55 11
+58 96 21 50 53
+51 60 67 64 71
+12 25 44 47 39
+15 92 81  9 38
+
+98 16 31 21 30
+58 10  3 89  7
+79 20 60 74 26
+86  4 83 96 15
+94 29 44 41 34
+
+50 75 83 20 52
+65 85 41 78 38
+31 64 86 32 10
+25 82 13 61 22
+11 73  4 77 24
+
+56 74 26 20 62
+83 46 41 24 52
+34 28 76 80 36
+75 48 63 17 55
+69 47 22 45 60
+
+17 15 71 28 68
+12 76 27 25 14
+34 39 31 58 13
+75 67  2 26 42
+72 43  0 23 54
+
+37 43 18 76 47
+96  1 80 77 27
+13 89 16  4  6
+74 92 55 99 38
+19 75 52 85 81
+
+69 51 39 95 98
+90 61 91  6 21
+25 57 81 10 49
+67 55 43 96 17
+78 11  3 64 77
+
+51 66  8 62 60
+82 94 24 54 26
+59 91 97 37 77
+20 25 69 98 84
+38 12 65 35 61
+
+ 7 26 91 84 17
+23 52 86 19 24
+58 44  5 32 40
+ 6 27 89 76 92
+33 10 90 83 82
+
+44 61 68 70 87
+23 17 90 93 21
+92 54 95 46 14
+47 24 89 33 31
+26 80 35 42 78
+
+88 80 50 46 26
+ 1 97 92 51 74
+16 24 40 31 95
+47 85 61 99 12
+27  8 25 42 13
+
+ 8 59 37 87 44
+62  0 67 39 92
+79 81 54 24 93
+56 84 23 18 34
+72 68 29 11 91
+
+64 51 81 44 12
+49 20 23 36 53
+59 73 37 60 57
+96 65  5 43 14
+46 31 47 87  1
+
+11 13 72 30  3
+67 20 84 59 77
+52 87 97 51 16
+43 36 21 33 82
+41 96 91 93 29
+
+ 7 31 19 87 94
+92 68 18 57 23
+ 5 88 81 86 10
+99 50 37 33 25
+97 22  0 53 91
+
+78 39 41 44 89
+91 82 71 42 37
+25 93 67 53  9
+84 23 33 92 14
+74 45 57 86 50
+
+79 83 10 85 48
+51 29 93 87 21
+58  5 52 37 99
+80  1 18 46 42
+60 92  0 44 59
+
+79 76 54 14 42
+57 11 39 66 33
+86 62 27 61 26
+48 68 47 99 46
+78 90  9 36 98
+
+76 79 66 38 65
+67 91 90 41 93
+ 2  1 33 56 50
+46  9  0 61 62
+26 58 16 24 10
+
+20 22 86 58 14
+53 74 54 85  6
+ 2 96 40 72 78
+99 81 16 31 55
+11 57 62 51 32
+
+ 8 51 73 40 88
+83 35 37 98 27
+ 3 42 15 14 33
+ 2 38 52 82 71
+67 55  9 66 53
+
+94 99 54 18 14
+40 56 57 66 68
+28 74 48 30  0
+59  1 22 50 23
+13 71  6 26 15
+
+28 60 66 25 56
+49 68 84 10 38
+73 50 87 16 14
+79 26 29 18  2
+57 22  5 48 91
+
+61 78  3 95 87
+ 6 62 25 74 84
+22 71 93 57 20
+81 33 15 45 96
+38 14 19 72 26
+
+51 19 62 72 39
+36 83  6 33  9
+95 43 42  2 22
+94 99 23 97 11
+66 61 16 30 35
+
+51 38  7 24 82
+23 12 46 55 85
+43 97 45 61 67
+53  2 77 99 34
+17 93 25  9 72
+
+37 32 35 63 93
+40 16 51 99 88
+73 69 49 80 33
+56 54 18 87 71
+29 98 85 58 17
+
+38  4 55 72 33
+29 63 86 52 75
+ 7 47 34 53 14
+89 39 83 36 78
+ 6 21 15 18 96
+
+56 19 40  0  7
+61 33 50 66 54
+93 91 64  6 45
+51 90 94 18 37
+15 28 13  2 44
+
+18 79  4 56 15
+38 80  8 42  5
+60 11 53 23 27
+ 9 71 19 83 72
+39 97 98 99  7
+
+90 22 41 95 15
+20 18  7 70 49
+97 51 79 94 77
+31 89 50 40  9
+37 84  6 98 35
+
+38 56 94 55  0
+92 84  8 85 73
+86 81 76 35  1
+62  5 59 77 72
+79 97 60 11 70
+
+43 98 87 97 70
+53 55 35  8 64
+80 59 75 11  2
+17 95 13 38 90
+31 20 60 84  4
+
+38 19 10 73 86
+37 72 66 22 53
+ 6 41 20 21 92
+ 0 13  9 89 17
+43 61 80 60 65
+
+61 50 42 99 26
+11 51 52 83 64
+92 60  2 91 20
+95 10 14 94 98
+ 5 37 90 17 69
+
+82 48 51 32 78
+30 39 10 84 69
+94  5 60 92 89
+95 31 64 67 23
+96 20 33 66 61
+
+33 92 78 24 74
+45 34 73  5 57
+18 37 69 44 38
+25 30 53 87 64
+28 23 14 10 81
+
+39 82 40 64 86
+26 81  3 85 50
+71 75 91 65 96
+17 55  8 56 59
+22 36 73 90  0
+
+18 67 50 70 71
+83  8 75 55 29
+66 33 39 88 16
+32 84 78 59  0
+11  3 61 65 36
+
+ 1 12 66 59  9
+24 97 75 83 11
+45 16 14 31 71
+85 43 99 18 15
+61 56 80 69 29
+
+18 50 86 53 71
+67 36 14 24 55
+52 30 33 54 81
+72 51 39 28 42
+45 98 78 35 73
+
+60 86 68 58 37
+17 78 43 31 96
+33 61 34 45 36
+10 29 83 98  2
+88 73  7 84 50
+
+30 21 94 31  4
+20 68 91 55 51
+10 98  2 25 84
+64 97 29 28 58
+75 17 76 54 65
+
+17 11 88  9 66
+ 1 59 60 79 55
+30 46 83 67 91
+23 45 99 90  6
+81 33  8 13 76
+
+25 68 43 59 51
+56 14 41 52 16
+62 36 12 37 71
+83 90 81 91  0
+95 92 29 54 26
+
+53 84 85 18 10
+51 44 87 86 67
+ 4 81 82 77 30
+26 68 80 57 71
+22 83 47 61 14
+
+41 89 38 14 66
+70 92 26 97 53
+78 25  5  4 48
+54 86 31 23  0
+99 73  6 20 98
+
+18 81 96 60 47
+59 87 95 15 57
+34 17 26  7 42
+25 90 45 94  5
+10 41 32 20 98
+
+37  9 20 82 83
+84 14 62  3 76
+86 67 95 40 65
+57 26  1 19 69
+49 41 29 35 13
+
+29 74 69 92 48
+80 47 59 18 13
+98  5 64 89 83
+37 97 90 32 49
+25 87 39 21 63
+
+ 1 61  5 82 66
+87 75 18 23 63
+38 51 33 59  4
+21 14 17 97 92
+94 45 84 22 10
+
+86 93  8 99 54
+ 1  4 37 30 34
+80 17 50 74 97
+28 11  6 85 78
+94 76 92 63 79
+
+63 87 89 19 81
+72 90 71 96 16
+85 92 78 11 37
+50 17 68 82 66
+21  9 39 69 73
+
+30 63 90  5 45
+26 15 28 84 65
+ 1 23  0 12 17
+61 98 21 39 56
+67 51  3  8 42
+
+54 91  9 70 93
+75 58 89 53 19
+77 64 45 78 14
+ 7 31 99 42 51
+87 95 60 10 84
+
+98 35 66 42 85
+75 27 97 54  9
+16 15 60 44 49
+28 19 51 24 50
+59 18 37 88 39
+
+69 29 49  9 76
+ 4 83 64 33  2
+67 81 88 70 39
+85 73 97 15  8
+ 7 13 26 12  1
+
+57  3 65 28 87
+36 31 51 19  0
+56 77 41 20 76
+79 29 80 60 66
+55 61  8 30 15
+
+ 2 42  3 17 40
+10 56 91 52 23
+76 39 75 82 49
+50 36 99  9 53
+92 66 48 31 41
+
+16 51 80 95 23
+36 84 33 56 11
+49 46 32 78 85
+67 29 94 26 22
+76  6 30 37  0
+
+27 94 79 48  4
+55 81 22 18 88
+93 15 59 41 11
+67 43 24 92 65
+ 5  1 60 99 62
+
+ 2 51 42 84 82
+80 28 43 93 72
+81 57 13 45 66
+34 22 53 37  3
+31 46 70 77 79
+
+17 12 22 53 74
+23 49 52 60 40
+64 98 97 75 57
+58 81 85 89 92
+42 34 65 87 18
+
+13  8 54 25 11
+84 72 66 78  1
+22 82 48 85 62
+68 99 18  3 57
+64 41 80 94 71
+
+45  5 56 30 62
+10 50 78 13 34
+90 97 85 36  0
+86 35 80 55 74
+47 99 59 61 18
+
+79 87 81 45 95
+24 91 27 18 16
+51 35 34 46 48
+39 40  6 70 99
+ 1 82 63 32 50
+
+78 68 27 17 65
+74 15 21 38 24
+82 97 49  7 58
+19 23 87 79 22
+57 93 30  1 69
+
+64 13 40 21 89
+ 3 95 20 79 59
+80 46 91 54  1
+62 66 30 60 47
+26 99 55 25  2
+
+47 83  7 71 81
+ 9 72 12 20 96
+28 57 82 98 42
+34 59 18 69  1
+68 38 46 19 80
+
+43 39 48 84 87
+32 78  5 65 50
+86 13 20 22 70
+31  6 52 53 18
+73 25  4 60 99
+
+48 15 59 50 33
+93 99 46 70 21
+91 26 76 65 87
+10 27 78  5 96
+ 4 63 22 82 20
+
+88 63 66 48 37
+39 47 56 52 27
+81 18 33 12 59
+ 3 96 55 26 43
+42  4  7 28 22
+
+95 12 98 84 23
+37 35 78  9 61
+52 47 24 90 17
+55 87 18 80 41
+38  0 14 36 48
+
+62 72 56 78  8
+75 26 11 58 91
+38 74 52 65 45
+43 41 15 82 35
+89 27 21 54  0
+
+43 36 85 68 60
+26 89 84 10 80
+87 50 75 81 35
+12 46  6 70 59
+93 51 66 33 49
+
+68 32  0 63 54
+20 92 39 89 17
+48 60 87 36 14
+93 76 83 10 55
+64 74 80 11 41
+
+ 9 32 11 41 87
+78 22  8 72 75
+ 6 51 29 90 50
+21 68 47  2  7
+52 19 36 57 58
+
+83 36 25 31 99
+86 29 47 77 38
+13 51 20 59 27
+74 50  9 11 44
+52 95 81  2 70
+
+96 47 14 73 59
+84 87  7  4 46
+60 27 79 53 30
+58 28 55  5 43
+91 75 63 35 52
+
+41 66 27 50 56
+76 60 80 85 23
+ 3 21 37 74 95
+ 9 92 43  5 98
+79 49 88 24 70
+
+59 18 57 90 13
+79 29 12  2  0
+84 58 38 77 96
+33 89 43 11 44
+93 23 98 60 51
+
+58 86 28 17  1
+ 6  4 81 55 53
+84 27 38 12 83
+50 43 40 85 88
+26 72 25 41 44
+
+14 92  7 98 12
+44 11 71 64 26
+88  8  2 56  6
+59  0 15 33 51
+10 52 89 53 34
+
+52  4  5 63 50
+15  8 60 70 13
+33 79 21 39 34
+84 91 30 12 71
+61 31 41  9 66
+
+43 67 52 92 54
+17 21 71 78 60
+19  0 88 61  2
+14 66 87 12 37
+89 23 25  4 24
+
+41 62  7 66 33
+59 87 84 80 71
+73 97 25 85 60
+86 64 61 54 83
+22 18 63 81 27
+
+92 89 50 11 73
+41 48 62 80 78
+46 55 81 16 94
+97 45  5 13 40
+14 75 22 42  2
diff --git a/2021/day4/src/main.rs b/2021/day4/src/main.rs
new file mode 100644
index 0000000..4b2f9b3
--- /dev/null
+++ b/2021/day4/src/main.rs
@@ -0,0 +1,107 @@
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+
+fn part1(grids: &Vec<Vec<u32>>, mut inputs: Vec<u32>) -> u32 {
+    let mut values = Vec::<u32>::new();
+
+    for _ in 0..4 {
+        values.push(inputs.remove(0));
+    }
+
+    let mut winner: i8 = -1;
+    for input in inputs {
+        if winner >= 0 {
+            break;
+        }
+        values.push(input);
+        for i in 0..grids.len() {
+            // Search by rows
+            for j in [0, 5, 10, 15, 20] {
+                let mut n = 0;
+                for k in 0..5 {
+                    let x = grids[i][j + k];
+                    if values.iter().any(|&i| i == x) {
+                        n += 1;
+                    }
+                }
+                if n == 5 {
+                    winner = i as i8;
+                }
+            }
+
+            // Search by cols
+            if winner < 0 {
+                for j in 0..5 {
+                    let mut n = 0;
+                    for k in [0, 5, 10, 15, 20] {
+                        let x = grids[i][j + k];
+                        if values.iter().any(|&i| i == x) {
+                            n += 1;
+                        }
+                    }
+                    if n == 5 {
+                        winner = i as i8;
+                    }
+                }
+            }
+
+            if winner >= 0 {
+                break;
+            }
+        }
+    }
+
+    let mut sum = 0;
+    for x in &grids[winner as usize] {
+        if values.iter().any(|&i| i == *x) {
+            continue;
+        }
+
+        sum += x;
+    }
+
+    sum * values.pop().unwrap()
+}
+
+fn main() -> std::io::Result<()> {
+    let file = File::open("input.txt")?;
+    let reader = BufReader::new(file);
+    let mut lines = reader.lines();
+
+    let inputs: Vec<_> = lines
+        .next()
+        .unwrap()
+        .unwrap()
+        .trim()
+        .split(',')
+        .map(|x| x.parse::<u32>().unwrap())
+        .collect::<Vec<u32>>();
+
+    let mut grids: Vec<Vec<u32>> = vec![];
+    let mut n: usize = 0;
+
+    lines.next(); // Ignore the first empty line
+    while let Some(line) = lines.next() {
+        let mut line = line.unwrap();
+        grids.push(Vec::with_capacity(5 * 5));
+
+        for _ in 0..5 {
+            grids[n].extend(
+                line.trim()
+                    .split(' ')
+                    .filter(|x| !x.is_empty())
+                    .map(|x| x.parse::<u32>().unwrap())
+                    .collect::<Vec<u32>>(),
+            );
+            line = match lines.next() {
+                Some(x) => x.unwrap(),
+                None => "".to_string(),
+            };
+        }
+        n += 1;
+    }
+
+    println!("{}", part1(&grids, inputs.clone()));
+
+    Ok(())
+}