Commit 03abac382457e071540314d050e21799b59b1d5b | zig

2 files changed, 38 insertions(+), 1 deletions(-)

lib/std/math/big/int.zig+12-1

...	...	@@ -3228,8 +3228,19 @@ pub const Managed = struct {
3228	3228
3229	3229	/// r = ⌊√a⌋
3230	3230	pub fn sqrt(rma: Managed, a: const Managed) !void {
3231		const needed_limbs = calcSqrtLimbsBufferLen(a.bitCountAbs());
	3231	const bit_count = a.bitCountAbs();
3232	3232
	3233	if (bit_count == 0) {
	3234	try rma.set(0);
	3235	rma.setMetadata(a.isPositive(), rma.len());
	3236	return;
	3237	}
	3238
	3239	if (!a.isPositive()) {
	3240	return error.SqrtOfNegativeNumber;
	3241	}
	3242
	3243	const needed_limbs = calcSqrtLimbsBufferLen(bit_count);
3233	3244	const limbs_buffer = try rma.allocator.alloc(Limb, needed_limbs);
3234	3245	defer rma.allocator.free(limbs_buffer);
3235	3246

lib/std/math/big/int_test.zig+26

...	...	@@ -3149,3 +3149,29 @@ test "big.int.Const.order 0 == -0" {
3149	3149	};
3150	3150	try std.testing.expectEqual(std.math.Order.eq, a.order(b));
3151	3151	}
	3152
	3153	test "big.int.Managed sqrt(0) = 0" {
	3154	const allocator = testing.allocator;
	3155	var a = try Managed.initSet(allocator, 1);
	3156	defer a.deinit();
	3157
	3158	var res = try Managed.initSet(allocator, 1);
	3159	defer res.deinit();
	3160
	3161	try a.setString(10, "0");
	3162
	3163	try res.sqrt(&a);
	3164	}
	3165
	3166	test "big.int.Managed sqrt(-1) = error" {
	3167	const allocator = testing.allocator;
	3168	var a = try Managed.initSet(allocator, 1);
	3169	defer a.deinit();
	3170
	3171	var res = try Managed.initSet(allocator, 1);
	3172	defer res.deinit();
	3173
	3174	try a.setString(10, "-1");
	3175
	3176	try testing.expectError(error.SqrtOfNegativeNumber, res.sqrt(&a));
	3177	}