41 lines
990 B
D
41 lines
990 B
D
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import std;
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void main()
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{
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File("input", "r").byLine.map!(to!int)
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.array.calculateJoltDifferences.multiply1And3Differences.writeln;
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}
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auto multiply1And3Differences(int[int] differences)
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{
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return differences[1] * differences[3];
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}
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int[int] calculateJoltDifferences(int[] input)
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{
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input.sort();
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int[int] differenceCounts;
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chain([0], input, [input.back + 3]).slide(2).map!(pair => pair[1] - pair[0])
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.each!(difference => differenceCounts[difference]++);
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return differenceCounts;
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}
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unittest
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{
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auto input = [16, 10, 15, 5, 1, 11, 7, 19, 6, 12, 4];
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auto differences = input.calculateJoltDifferences;
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assert(differences[1] == 7 && differences[3] == 5);
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}
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unittest
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{
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auto input = [
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28, 33, 18, 42, 31, 14, 46, 20, 48, 47, 24, 23, 49, 45, 19, 38, 39, 11,
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1, 32, 25, 35, 8, 17, 7, 9, 4, 2, 34, 10, 3
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];
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auto differences = input.calculateJoltDifferences;
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assert(differences[1] == 22 && differences[3] == 10);
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}
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