diff options
Diffstat (limited to 't/helper/test-mergesort.c')
| -rw-r--r-- | t/helper/test-mergesort.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/t/helper/test-mergesort.c b/t/helper/test-mergesort.c index 27ba252d4a..d71ef568f3 100644 --- a/t/helper/test-mergesort.c +++ b/t/helper/test-mergesort.c @@ -150,6 +150,34 @@ static void mode_dither(int *arr, int n) arr[i] += i % 5; } +static void unriffle(int *arr, int n, int *tmp) +{ + int i, j; + COPY_ARRAY(tmp, arr, n); + for (i = j = 0; i < n; i += 2) + arr[j++] = tmp[i]; + for (i = 1; i < n; i += 2) + arr[j++] = tmp[i]; +} + +static void unriffle_recursively(int *arr, int n, int *tmp) +{ + if (n > 1) { + int half = n / 2; + unriffle(arr, n, tmp); + unriffle_recursively(arr, half, tmp); + unriffle_recursively(arr + half, n - half, tmp); + } +} + +static void mode_unriffle(int *arr, int n) +{ + int *tmp; + ALLOC_ARRAY(tmp, n); + unriffle_recursively(arr, n, tmp); + free(tmp); +} + #define MODE(name) { #name, mode_##name } static struct mode { @@ -162,6 +190,7 @@ static struct mode { MODE(reverse_2nd_half), MODE(sort), MODE(dither), + MODE(unriffle), }; static const struct mode *get_mode_by_name(const char *name) |