hello.go

package main

import (
	"fmt"
	"hello-go/grammar/note"
	"strings"
)

func main() {
	wordBreak("catsanddog", []string{"cat", "cats", "and", "sand", "dog"})
	fmt.Println("hello world!") // in current function
	sayHello()                  // in current file
	//speakHello()                // in current package
	note.SayHello() // in other package

	fmt.Println()
}

func sayHello() {
	fmt.Println("hello!")
}
func wordBreak(s string, wordDict []string) []string {
	dictMap := make(map[string]bool)
	maxLen := 0
	for _, w := range wordDict {
		dictMap[w] = true
		if len(w) > maxLen {
			maxLen = len(w)
		}
	}

	result := make([][]string, 0)

	var helper func(reminder string, words []string)
	helper = func(reminder string, words []string) {
		if len(reminder) == 0 {
			result = append(result, words)
			return
		}
		for i := 1; i <= min(maxLen, len(reminder)); i++ {
			w := reminder[:i]
			if dictMap[w] {
				newWords := make([]string, len(words))
				copy(newWords, words)
				newWords = append(newWords, w)
				helper(reminder[i:], newWords)
			}
		}
	}

	helper(s, []string{})
	ans := make([]string, len(result))
	for i := 0; i < len(result); i++ {
		wordList := result[i]
		ans[i] = strings.Join(wordList, " ")
	}
	return ans
}

func min(a int, b int) int {
	if a < b {
		return a
	}
	return b
}