Feature #14401 » inverse_of_digits.patch
| numeric.c | ||
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}
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}
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static VALUE
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rb_int_s_from_digits(int argc, VALUE *argv, VALUE klass) {
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VALUE digits, base, array;
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long size, levels, level;
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rb_check_arity(argc, 1, 2);
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digits = rb_to_array_type(argv[0]);
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base = argc == 2 ? rb_to_int(argv[1]) : INT2FIX(10);
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if (FIXNUM_P(base) && FIX2LONG(base) < 2)
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rb_raise(rb_eArgError, "invalid radix %ld", FIX2LONG(base));
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else if (RB_TYPE_P(base, T_BIGNUM) && BIGNUM_NEGATIVE_P(base))
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rb_raise(rb_eArgError, "negative radix");
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array = rb_ary_dup(digits);
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size = RARRAY_LEN(array);
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levels = bit_length(size);
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for (level = 0; level < levels; level++) {
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long stride = 2 << level;
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long i, n = (size + stride - 1) / stride;
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if (level) base = rb_int_mul(base, base);
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for (i = 0; i < n; i++) {
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VALUE div = INT2FIX(0);
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VALUE mod = rb_to_int(RARRAY_AREF(array, 2 * i));
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RARRAY_ASET(array, 2 * i, INT2FIX(0));
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if (2 * i + 1 < size) {
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div = rb_to_int(RARRAY_AREF(array, 2 * i + 1));
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RARRAY_ASET(array, 2 * i + 1, INT2FIX(0));
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}
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if (div == INT2FIX(0)) {
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RARRAY_ASET(array, i, mod);
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} else {
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div = rb_to_int(div);
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RARRAY_ASET(array, i, rb_int_plus(rb_int_mul(div, base), mod));
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}
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}
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}
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return RARRAY_AREF(array, 0);
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}
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/*
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* Document-class: ZeroDivisionError
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*
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| ... | ... | |
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rb_undef_alloc_func(rb_cInteger);
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rb_undef_method(CLASS_OF(rb_cInteger), "new");
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rb_define_singleton_method(rb_cInteger, "sqrt", rb_int_s_isqrt, 1);
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rb_define_singleton_method(rb_cInteger, "from_digits", rb_int_s_from_digits, -1);
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rb_define_method(rb_cInteger, "to_s", int_to_s, -1);
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rb_define_alias(rb_cInteger, "inspect", "to_s");
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| test/ruby/test_integer.rb | ||
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assert_equal([0, 1], 10.digits(o))
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end
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def test_from_digits
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assert_equal(Integer.from_digits([0]), 0)
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assert_equal(Integer.from_digits([1]), 1)
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assert_equal(Integer.from_digits([4, 3, 2, 1]), 1234)
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assert_equal(Integer.from_digits([1, 0, 1, 1, 1], 2), 29)
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assert_equal(Integer.from_digits((9**999).digits), 9**999)
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assert_equal(Integer.from_digits([1, 1, 1], 1 << 128), (1 << 256) | (1 << 128) | 1)
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assert_raise(TypeError) { Integer.from_digits("4321") }
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assert_raise(TypeError) { Integer.from_digits([4, 3, 2, 1], "10") }
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assert_raise(TypeError) { Integer.from_digits([4, "3", 2, 1]) }
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assert_raise(ArgumentError) { Integer.from_digits([4, 3, 2, 1], 1) }
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assert_raise(ArgumentError) { Integer.from_digits([4, 3, 2, 1], 0) }
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assert_raise(ArgumentError) { Integer.from_digits([4, 3, 2, 1], -9**999) }
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end
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def test_square_root
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assert_raise(TypeError) {Integer.sqrt("x")}
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assert_raise(Math::DomainError) {Integer.sqrt(-1)}
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