+void sort_and_compact_ranges(Range *ranges, unsigned *n_ranges)
+{
+ unsigned i, j;
+
+ if(!*n_ranges)
+ return;
+
+ qsort(ranges, *n_ranges, sizeof(Range), &range_cmp);
+ for(i=0, j=1; j<*n_ranges; ++j)
+ {
+ if(ranges[i].last+1>=ranges[j].first)
+ {
+ if(ranges[j].last>ranges[i].last)
+ ranges[i].last = ranges[j].last;
+ }
+ else
+ {
+ ++i;
+ if(i!=j)
+ ranges[i] = ranges[j];
+ }
+ }
+
+ *n_ranges = i+1;
+}
+
+int range_cmp(const void *p1, const void *p2)
+{
+ const Range *r1 = (const Range *)p1;
+ const Range *r2 = (const Range *)p2;
+ if(r1->first!=r2->first)
+ return (r1->first<r2->first ? -1 : 1);
+ else if(r1->last!=r2->last)
+ return (r1->last<r2->last ? -1 : 1);
+ else
+ return 0;
+}
+