zjysource的专栏

Exercise: Fibonacci closure Let's have some fun with functions. Implement a fibonacci function that returns a function (a closure) that returns successive fibonacci numbers (0, 1, 1, 2, 3, 5,

Exercise: Equivalent Binary Trees There can be many different binary trees with the same sequence of values stored at the leaves. For example, here are two binary trees storing the sequence 1, 1, 2

Exercise: Images Remember the picture generator you wrote earlier? Let's write another one, but this time it will return an implementation of image.Image instead of a slice of data. Define you

Exercise: rot13Reader A common pattern is an io.Reader that wraps another io.Reader, modifying the stream in some way. For example, the gzip.NewReader function takes an io.Reader (a stream o

Exercise: Readers Implement a Reader type that emits an infinite stream of the ASCII character'A'. package main import "golang.org/x/tour/reader" type MyReader struct{} func (r MyReader) Read

Exercise: Errors Copy your Sqrt function from the earlier exercise and modify it to return an error value. Sqrt should return a non-nil error value when given a negative number, as it doesn't

Exercise: Loops and Functions As a simple way to play with functions and loops, implement the square root function using Newton's method. In this case, Newton's method is to approximate Sqrt(x)

Exercise: Maps Implement WordCount. It should return a map of the counts of each “word” in the string s. The wc.Test function runs a test suite against the provided function and prints success or

Exercise: Slices Implement Pic. It should return a slice of length dy, each element of which is a slice of dx 8-bit unsigned integers. When you run the program, it will display your picture, in

Exercise: Stringers Make the IPAddr type implementfmt.Stringer to print the address as a dotted quad. For instance, IPAddr{1, 2, 3, 4} should print as "1.2.3.4". package main import "fmt"

Exercise: Web Crawler In this exercise you'll use Go's concurrency features to parallelize a web crawler. Modify the Crawl function to fetch URLs in parallel without fetching the same URL twice.