func plagiarismCheck(code1, code2 []string) bool {
	c1 := strings.Join(code1, " ")
	c2 := strings.Join(code2, " ")
	if c1 == c2 {
		return false
	}

	wordRe := regexp.MustCompile(`[\w]+`)
	numericRe := regexp.MustCompile(`^[0-9]+$`)

	d1 := wordRe.FindAllString(c1, -1)
	d2 := wordRe.FindAllString(c2, -1)

	rCand := make(map[string]string)
	var order []string
	for k, v := range d1 {
		if k >= len(d2) {
			break
		}
		if v != d2[k] && !numericRe.MatchString(v) {
			if _, exists := rCand[v]; !exists {
				order = append(order, v)
			}
			rCand[v] = d2[k]
		}
	}

	// Two-pass rename: stash originals behind a placeholder first so that
	// swapping two identifiers (e.g. a<->b) doesn't clobber itself, then
	// swap the placeholders in for the real replacements.
	for _, orig := range order {
		re1 := regexp.MustCompile(`(\W)` + regexp.QuoteMeta(orig) + `(\W*)`)
		c1 = re1.ReplaceAllString(c1, "${1}PLACEHOLDER"+orig+"$2")
		re2 := regexp.MustCompile(`(\W)` + regexp.QuoteMeta(orig))
		c1 = re2.ReplaceAllString(c1, "${1}PLACEHOLDER"+orig)
	}

	for _, orig := range order {
		repl := rCand[orig]
		re3 := regexp.MustCompile(`(\W)PLACEHOLDER` + regexp.QuoteMeta(orig) + `(\W)`)
		c1 = re3.ReplaceAllString(c1, "${1}"+repl+"$2")
		re4 := regexp.MustCompile(`(\W)PLACEHOLDER` + regexp.QuoteMeta(orig))
		c1 = re4.ReplaceAllString(c1, "${1}"+repl)
	}

	return c1 == c2
}