Step by Step solution about How to resolve the algorithm Jewels and stones step by step in the Go programming language

The provided code defines a function js that takes two strings as input: stones and jewels. The function returns an integer representing the number of unique characters in stones that are also present in jewels.

There are four different implementations of the js function in the code. Each implementation uses a different approach to solve the problem:

1. Byte Loop and String Index Search: In this implementation, the function iterates over each byte in the stones string using a range loop. For each byte, it checks if the byte is present in the jewels string by using the strings.IndexByte function. If the byte is found, the n counter is incremented.

2. Byte Loop and String Count: This implementation is similar to the previous one, but instead of using the strings.IndexByte function, it uses the strings.Count function to count the number of occurrences of each byte in the stones string that matches a byte in the jewels string.

3. Byte Loop and Set Lookup: This implementation creates a set of bytes from the jewels string. Then, it iterates over each byte in the stones string and checks if the byte is present in the set. If the byte is found, the n counter is incremented.

4. Byte Loop and Counter Map: This implementation creates a map of bytes from the stones string, where the keys are the bytes and the values are the number of occurrences of each byte. Then, it iterates over each byte in the jewels string and checks if the byte is present in the map. If the byte is found, the n counter is incremented by the number of occurrences of that byte in the stones string.

The provided code also includes a main function that demonstrates the usage of the js function. In the main function, the js function is called with two input strings: "aAAbbbb" and "aA". The result, which is the number of unique characters in "aAAbbbb" that are also present in "aA", is printed to the console.

package main
  
import (
    "fmt"
    "strings"
)

func js(stones, jewels string) (n int) {
    for _, b := range []byte(stones) {
        if strings.IndexByte(jewels, b) >= 0 {
            n++
        }
    }
    return
}

func main() {
    fmt.Println(js("aAAbbbb", "aA"))
}


func js(stones, jewels string) (n int) {
    for _, b := range []byte(jewels) {
        n += strings.Count(stones, string(b))
    }
    return
}


func js(stones, jewels string) (n int) {
    var jSet ['z' + 1]int
    for _, b := range []byte(jewels) {
        jSet[b] = 1
    }
    for _, b := range []byte(stones) {
        n += jSet[b]
    }
    return
}


func js(stones, jewels string) (n int) {
    var sset ['z' + 1]int
    for _, b := range []byte(stones) {
        sset[b]++
    }
    for _, b := range []byte(jewels) {
        n += sset[b]
    }
    return
}