My solution to the problem i posted earlier

gistfile1.go

//Check whether the given subsequence occurs in the src
func SubsequenceOccurs(src, seq []byte) bool {
	for i := 0; i < len(src) - len(seq); i++  {
		if src[i] == seq[0] {
			j := 1
			for ; j < len(seq); j++ {
				if src[i + j] != seq[j] {
					break
				}
			}
			if j == len(seq) {
				return true
			}
		}
	}
	return false
}

func LongestRecurringSubsequence(src []byte) []byte {
	l := int(len(src) / 2)
	//starting at length l and moving down by one each time
	for ; l > 0; l-- {
		//For each subsequence S of length l
		for i := 0; i < len(src) - l; i++ {
			S := src[i:i+l]
			//if S occurs in (src - S)
			if SubsequenceOccurs(src[:i], S) || SubsequenceOccurs(src[i+l:], S) {
				return S
			}
		}
	}
	return nil
}