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.github, docs, exercises: bump Zig from 0.11.0 to 0.12.0 (#392)
Zig 0.12.0 was released on 2024-04-20. See the release notes [1]. Also simplify the sieve example implementation again for now, essentially reverting a previous commit [2]. With 0.12.0, the previous implementation produced the error: Running tests for sieve... ./bin/run-tests: line 23: 2287 Trace/breakpoint trap (core dumped) zig test "test_${exercise_name}.zig" [1] https://ziglang.org/download/0.12.0/release-notes.html [2] 1bcf8f1, 2023-03-23, "exercises(sieve): example: generate primes at compile time"
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Original file line number | Diff line number | Diff line change |
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@@ -1,53 +1,29 @@ | ||
const std = @import("std"); | ||
const assert = std.debug.assert; | ||
const sqrt = std.math.sqrt; | ||
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/// Returns bools, where the value at index `i` is `true` iff `i` is a prime number. | ||
fn eratosthenes(comptime n: u32) []const bool { | ||
var result = [_]bool{false} ** (n + 1); | ||
result[2] = true; | ||
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var i = 3; | ||
while (i <= n) : (i += 2) { | ||
result[i] = true; | ||
} | ||
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i = 3; | ||
while (i <= sqrt(n)) : (i += 2) { // Optimization: stop at sqrt(n) | ||
if (result[i]) { | ||
var j = i * i; // Optimization: start at i*i | ||
while (j < n) : (j += 2 * i) { | ||
result[j] = false; | ||
} | ||
} | ||
} | ||
return &result; | ||
} | ||
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/// Returns the prime numbers up to `limit`. | ||
fn genPrimes(comptime limit: u32) []const u32 { | ||
@setEvalBranchQuota(limit * 3); | ||
const bools = comptime eratosthenes(limit); | ||
// See https://en.wikipedia.org/wiki/Prime-counting_function#Inequalities | ||
const upper_bound_count = @ceil(1.25506 * @as(f64, limit) / @log(@as(f64, limit))); | ||
var result: [upper_bound_count]u32 = undefined; | ||
var j = 0; | ||
for (bools, 0..) |b, i| { | ||
if (b) { | ||
result[j] = i; | ||
j += 1; | ||
} | ||
} | ||
return result[0..j]; | ||
} | ||
const assert = @import("std").debug.assert; | ||
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pub fn primes(buffer: []u32, comptime limit: u32) []const u32 { | ||
const sieve_limit = 1000; | ||
comptime assert(limit <= sieve_limit); | ||
const p = comptime genPrimes(sieve_limit); // The primes up to the sieve limit. | ||
comptime assert(limit <= 1000); | ||
const primes_under_1000 = [_]u32{ | ||
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, | ||
31, 37, 41, 43, 47, 53, 59, 61, 67, 71, | ||
73, 79, 83, 89, 97, 101, 103, 107, 109, 113, | ||
127, 131, 137, 139, 149, 151, 157, 163, 167, 173, | ||
179, 181, 191, 193, 197, 199, 211, 223, 227, 229, | ||
233, 239, 241, 251, 257, 263, 269, 271, 277, 281, | ||
283, 293, 307, 311, 313, 317, 331, 337, 347, 349, | ||
353, 359, 367, 373, 379, 383, 389, 397, 401, 409, | ||
419, 421, 431, 433, 439, 443, 449, 457, 461, 463, | ||
467, 479, 487, 491, 499, 503, 509, 521, 523, 541, | ||
547, 557, 563, 569, 571, 577, 587, 593, 599, 601, | ||
607, 613, 617, 619, 631, 641, 643, 647, 653, 659, | ||
661, 673, 677, 683, 691, 701, 709, 719, 727, 733, | ||
739, 743, 751, 757, 761, 769, 773, 787, 797, 809, | ||
811, 821, 823, 827, 829, 839, 853, 857, 859, 863, | ||
877, 881, 883, 887, 907, 911, 919, 929, 937, 941, | ||
947, 953, 967, 971, 977, 983, 991, 997, | ||
}; | ||
_ = buffer; | ||
if (limit >= p[p.len - 1]) return p; | ||
if (limit >= primes_under_1000[primes_under_1000.len - 1]) return &primes_under_1000; | ||
var i: usize = 0; | ||
while (p[i] <= limit) : (i += 1) {} | ||
return p[0..i]; | ||
while (primes_under_1000[i] <= limit) : (i += 1) {} | ||
return primes_under_1000[0..i]; | ||
} |