Function dfs

go/0097-interleaving-string.go:17–37

(i, j int)

}

func dfs(i, j int) bool {
	if i >= len(st1) && j >= len(st2) {
		return true
	}

	val, ok := cache[[2]int{i, j}]
	
	if ok {
		return val
	}
	
	if i < len(st1) && st1[i] == st3[i+j] && dfs(i+1, j) {
		return true
	}
	if j < len(st2) && st2[j] == st3[i+j] && dfs(i, j+1) {
		return true
	}
	
	cache[[2]int{i, j}] = false
	return false
}