11 lines
237 B
D
11 lines
237 B
D
import std.stdio, std.algorithm, std.range;
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string[] g(in uint n) pure nothrow {
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return n ? g(n - 1).map!q{'0' ~ a}.array ~
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g(n - 1).retro.map!q{'1' ~ a}.array
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: [""];
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}
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void main() {
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4.g.writeln;
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}
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