* of the GNU Lesser General Public License.
*/
+/***
+ * [[defs]]
+ * Definitions
+ * -----------
+ ***/
+
+/**
+ * Find the first element not lower than @x in the sorted array @ary of @N elements (non-decreasing order).
+ * Returns the index of the found element or @N if no exists. Uses `ary_lt_x(ary,i,x)` to compare the @i'th element with @x.
+ * The time complexity is `O(log(N))`.
+ **/
#define BIN_SEARCH_FIRST_GE_CMP(ary,N,x,ary_lt_x) ({ \
- uns l = 0, r = (N); \
+ uint l = 0, r = (N); \
while (l < r) \
{ \
- uns m = (l+r)/2; \
+ uint m = (l+r)/2; \
if (ary_lt_x(ary,m,x)) \
l = m+1; \
else \
l; \
})
+/**
+ * The default comparision macro for @BIN_SEARCH_FIRST_GE_CMP().
+ **/
#define ARY_LT_NUM(ary,i,x) (ary)[i] < (x)
+/**
+ * Same as @BIN_SEARCH_FIRST_GE_CMP(), but uses the default `<` operator for comparisions.
+ **/
#define BIN_SEARCH_FIRST_GE(ary,N,x) BIN_SEARCH_FIRST_GE_CMP(ary,N,x,ARY_LT_NUM)
+
+/**
+ * Search the sorted array @ary of @N elements (non-decreasing) for the first occurence of @x.
+ * Returns the index or -1 if no such element exists. Uses the `<` operator for comparisions.
+ **/
#define BIN_SEARCH_EQ(ary,N,x) ({ int i = BIN_SEARCH_FIRST_GE(ary,N,x); if (i >= (N) || (ary)[i] != (x)) i=-1; i; })