Initial data commit

Task/Sort-using-a-custom-comparator/C/sort-using-a-custom-comparator.c

@@ -0,0 +1,22 @@
+#include <stdlib.h>  /* for qsort */
+#include <string.h>  /* for strlen */
+#include <strings.h> /* for strcasecmp */
+
+int mycmp(const void *s1, const void *s2)
+{
+    const char *l = *(const char **)s1, *r = *(const char **)s2;
+    size_t ll = strlen(l), lr = strlen(r);
+
+    if (ll > lr) return -1;
+    if (ll < lr) return 1;
+    return strcasecmp(l, r);
+}
+
+int main()
+{
+    const char *strings[] = {
+      "Here", "are", "some", "sample", "strings", "to", "be", "sorted" };
+
+    qsort(strings, sizeof(strings)/sizeof(*strings), sizeof(*strings), mycmp);
+    return 0;
+}