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author | nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2010-08-21 21:46:31 +0000 |
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committer | nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e> | 2010-08-21 21:46:31 +0000 |
commit | 119da02e87bb7a75a45ab4b45eadbfee53aa40b9 (patch) | |
tree | 40485da821b891610f10b7db032e4cfbf7e0ca71 | |
parent | 6eb922763f25537237865f976b42c52bd6ae3d1a (diff) | |
download | ruby-119da02e87bb7a75a45ab4b45eadbfee53aa40b9.tar.gz |
* array.c (RAND_UPTO): macro for random number.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@29067 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
-rw-r--r-- | ChangeLog | 4 | ||||
-rw-r--r-- | array.c | 24 |
2 files changed, 17 insertions, 11 deletions
@@ -1,3 +1,7 @@ +Sun Aug 22 06:46:21 2010 Nobuyoshi Nakada <nobu@ruby-lang.org> + + * array.c (RAND_UPTO): macro for random number. + Sun Aug 22 05:55:01 2010 Nobuyoshi Nakada <nobu@ruby-lang.org> * configure.in: fix typo. a patch from Eric Wong at @@ -3730,6 +3730,8 @@ rb_ary_flatten(int argc, VALUE *argv, VALUE ary) return result; } +#define RAND_UPTO(max) (long)(rb_genrand_real()*(max)) + /* * call-seq: * ary.shuffle! -> ary @@ -3747,7 +3749,7 @@ rb_ary_shuffle_bang(VALUE ary) rb_ary_modify(ary); ptr = RARRAY_PTR(ary); while (i) { - long j = (long)(rb_genrand_real()*i); + long j = RAND_UPTO(i); VALUE tmp = ptr[--i]; ptr[i] = ptr[j]; ptr[j] = tmp; @@ -3798,7 +3800,7 @@ rb_ary_sample(int argc, VALUE *argv, VALUE ary) len = RARRAY_LEN(ary); if (argc == 0) { if (len == 0) return Qnil; - i = len == 1 ? 0 : (long)(rb_genrand_real()*len); + i = len == 1 ? 0 : RAND_UPTO(len); return RARRAY_PTR(ary)[i]; } rb_scan_args(argc, argv, "1", &nv); @@ -3810,16 +3812,16 @@ rb_ary_sample(int argc, VALUE *argv, VALUE ary) switch (n) { case 0: return rb_ary_new2(0); case 1: - return rb_ary_new4(1, &ptr[(long)(rb_genrand_real()*len)]); + return rb_ary_new4(1, &ptr[RAND_UPTO(len)]); case 2: - i = (long)(rb_genrand_real()*len); - j = (long)(rb_genrand_real()*(len-1)); + i = RAND_UPTO(len); + j = RAND_UPTO(len-1); if (j >= i) j++; return rb_ary_new3(2, ptr[i], ptr[j]); case 3: - i = (long)(rb_genrand_real()*len); - j = (long)(rb_genrand_real()*(len-1)); - k = (long)(rb_genrand_real()*(len-2)); + i = RAND_UPTO(len); + j = RAND_UPTO(len-1); + k = RAND_UPTO(len-2); { long l = j, g = i; if (j >= i) l = i, g = ++j; @@ -3830,9 +3832,9 @@ rb_ary_sample(int argc, VALUE *argv, VALUE ary) if ((size_t)n < sizeof(idx)/sizeof(idx[0])) { VALUE *ptr_result; long sorted[sizeof(idx)/sizeof(idx[0])]; - sorted[0] = idx[0] = (long)(rb_genrand_real()*len); + sorted[0] = idx[0] = RAND_UPTO(len); for (i=1; i<n; i++) { - k = (long)(rb_genrand_real()*--len); + k = RAND_UPTO(--len); for (j = 0; j < i; ++j) { if (k < sorted[j]) break; ++k; @@ -3852,7 +3854,7 @@ rb_ary_sample(int argc, VALUE *argv, VALUE ary) ptr_result = RARRAY_PTR(result); RB_GC_GUARD(ary); for (i=0; i<n; i++) { - j = (long)(rb_genrand_real()*(len-i)) + i; + j = RAND_UPTO(len-i) + i; nv = ptr_result[j]; ptr_result[j] = ptr_result[i]; ptr_result[i] = nv; |