AoC 2020: day10

Signed-off-by: Ettore Dreucci <ettore.dreucci@gmail.com>

2020-python/inputs/day_10

@@ -0,0 +1,108 @@
+115
+134
+121
+184
+78
+84
+77
+159
+133
+90
+71
+185
+152
+165
+39
+64
+85
+50
+20
+75
+2
+120
+137
+164
+101
+56
+153
+63
+70
+10
+72
+37
+86
+27
+166
+186
+154
+131
+1
+122
+95
+14
+119
+3
+99
+172
+111
+142
+26
+82
+8
+31
+53
+28
+139
+110
+138
+175
+108
+145
+58
+76
+7
+23
+83
+49
+132
+57
+40
+48
+102
+11
+105
+146
+149
+66
+38
+155
+109
+128
+181
+43
+44
+94
+4
+169
+89
+96
+60
+69
+9
+163
+116
+45
+59
+15
+178
+34
+114
+17
+16
+79
+91
+100
+162
+125
+156
+65

2020-python/solutions/day_10.py

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+"""AOC 2020 Day 10"""
+
+import pathlib
+import time
+
+TEST_INPUT = """16
+10
+15
+5
+1
+11
+7
+19
+6
+12
+4"""
+
+TEST_INPUT_2 = """28
+33
+18
+42
+31
+14
+46
+20
+48
+47
+24
+23
+49
+45
+19
+38
+39
+11
+1
+32
+25
+35
+8
+17
+7
+9
+4
+2
+34
+10
+3"""
+
+def read_input(input_path: str) -> str:
+    """take input file path and return a str with the file's content"""
+    with open(input_path, 'r') as input_file:
+        input_data = input_file.read().strip()
+        return input_data
+
+def extract(input_data: str) -> list:
+    """take input data and return the appropriate data structure"""
+    entries = [0]
+    for entry in input_data.split('\n'):
+        entries.append(int(entry))
+    entries = sorted(entries)
+    entries.append(entries[-1]+3)
+    return entries
+
+def part1(entries: list) -> int:
+    """part1 solver"""
+    jolt_diff_1, jolt_diff_3 = 0, 0
+    for index in range(len(entries)-1):
+        diff = entries[index+1] - entries[index]
+        if diff == 1:
+            jolt_diff_1 += 1
+        elif diff == 3:
+            jolt_diff_3 += 1
+    return jolt_diff_1*jolt_diff_3
+
+def part2(entries: list) -> int:
+    """part2 solver"""
+    distinct_paths = [0]*(entries[-1]+1)
+    distinct_paths[0] = 1
+
+    for adapter in entries:
+        distinct_paths[adapter] += distinct_paths[adapter-1] + distinct_paths[adapter-2] + distinct_paths[adapter-3]
+
+    return distinct_paths[len(distinct_paths)-1]
+
+def test_input_day_10():
+    """pytest testing function"""
+    entries = extract(TEST_INPUT)
+    assert part1(entries) == 35
+    assert part2(entries) == 8
+    entries = extract(TEST_INPUT_2)
+    assert part1(entries) == 220
+    assert part2(entries) == 19208
+
+def test_bench_day_10(benchmark):
+    """pytest-benchmark function"""
+    benchmark(main)
+
+def main():
+    """main function"""
+    input_path = str(pathlib.Path(__file__).resolve().parent.parent) + "/inputs/" + str(pathlib.Path(__file__).stem)
+    start_time = time.time()
+    input_data = read_input(input_path)
+    entries = extract(input_data)
+    print("Part 1: %d" % part1(entries))
+    print("Part 2: %d" % part2(entries))
+    end_time = time.time()
+    print("Execution time: %f" % (end_time-start_time))
+
+if __name__ == "__main__":
+    main()

README.md

@@ -9,7 +9,7 @@
 ### Year [2020](https://adventofcode.com/2020/) - Python
 
 | Day                                            | Execution time                                 |
-| -------------------------------------------- | --------------------------------------------  |
+| ---------------------------------------------- | ---------------------------------------------- |
 | [Day 1](https://adventofcode.com/2020/day/1)   | [0.04ms](./2020-python/solutions/day_1.py)     |
 | [Day 2](https://adventofcode.com/2020/day/2)   | [0.702ms](./2020-python/solutions/day_2.py)    |
 | [Day 3](https://adventofcode.com/2020/day/3)   | [0.343ms](./2020-python/solutions/day_3.py)    |
@@ -18,6 +18,7 @@
 | [Day 6](https://adventofcode.com/2020/day/6)   | [2.587ms](./2020-python/solutions/day_6.py)    |
 | [Day 7](https://adventofcode.com/2020/day/7)   | [1.689ms](./2020-python/solutions/day_7.py)    |
 | [Day 8](https://adventofcode.com/2020/day/8)   | [6.313ms](./2020-python/solutions/day_8.py)    |
-| [Day 9](https://adventofcode.com/2020/day/9) | [7.2207ms](./2020-python/solutions/day_9.py) |
+| [Day 9](https://adventofcode.com/2020/day/9)   | [7.220ms](./2020-python/solutions/day_9.py)    |
+| [Day 10](https://adventofcode.com/2020/day/10) | [139.110ms](./2020-python/solutions/day_10.py) |