| 189 | // Returns the absolute difference between `lhs` and `rhs`. |
| 190 | template <typename T> |
| 191 | T absdiff(const T &lhs, const T &rhs) { |
| 192 | return lhs > rhs ? lhs - rhs : rhs - lhs; |
| 193 | } |
| 194 | |
| 195 | struct PairHasher { |
| 196 | template <typename T1, typename T2> |