Minimum Cover - Implementation

function videoStitching(clips, T)
 sort clips by start ascending
 count := 0
 curEnd := 0
 i := 0
 while curEnd < T
 maxEnd := curEnd
 while i < length of clips and clips[i].start <= curEnd
 maxEnd := max(maxEnd, clips[i].end)
 i := i + 1
 if maxEnd = curEnd then
 return -1 // Cannot extend further
 curEnd := maxEnd
 count := count + 1
 return count

Time: $O(n \log n)$. Space: $O(1)$ extra.