merge two sorted subs xs[i, m) and xs[j...n) to working area xs[w...]
(xs: &mut [T], mut i: usize, m: usize, mut j: usize, n: usize, mut w: usize)
| 135 | pub mod v3 { |
| 136 | // merge two sorted subs xs[i, m) and xs[j...n) to working area xs[w...] |
| 137 | fn wmerge<T>(xs: &mut [T], mut i: usize, m: usize, mut j: usize, n: usize, mut w: usize) |
| 138 | where |
| 139 | T: Ord, |
| 140 | { |
| 141 | while i < m && j < n { |
| 142 | if xs[i] < xs[j] { |
| 143 | xs.swap(w, i); |
| 144 | i += 1; |
| 145 | } else { |
| 146 | xs.swap(w, j); |
| 147 | j += 1; |
| 148 | } |
| 149 | w += 1; |
| 150 | } |
| 151 | |
| 152 | while i < m { |
| 153 | xs.swap(w, i); |
| 154 | i += 1; |
| 155 | w += 1; |
| 156 | } |
| 157 | |
| 158 | while j < n { |
| 159 | xs.swap(w, j); |
| 160 | j += 1; |
| 161 | w += 1; |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | /// sort xs[l, u), and put result to working area w. |
| 166 | /// constraint, len(w) == u - l |