代码随想录算法训练营|day8

344.反转字符串

文章详解

func reverseString(s []byte)  {
    l, r := 0, len(s) - 1
    for l < r {
        s[l], s[r] = s[r], s[l]
        l++
        r--
    }
    return
}

541.反转字符串II

文章详解

func reverseStr(s string, k int) string {
    n := len(s)
    ss := []byte(s)
    for i := 0; i < n; i += 2 * k {
        reverse(ss, i, min(i + k, n) - 1)
    }
    return string(ss)
}

func reverse(s []byte, l, r int) {
    for l < r {
        s[l], s[r] = s[r], s[l]
        l++
        r--
    }
    return
}

卡码网：54.替换数字

正则表达式替换

package main

import (
	"fmt"
	"regexp"
)

func main() {

	var str string
	fmt.Scanln(&str)
	re := regexp.MustCompile(`\d+`)
	newStr := re.ReplaceAllString(str, "number")
	fmt.Printf("%s", newStr)
}

151.反转字符串中的单词

文章详解

func reverseWords(s string) string {
	str := []byte(s)
	str = trim(str)
	reverse(str)

	l, r, n := 0, 0, len(str)
	for l < n {
		for r < n && str[r] != ' ' {
			r++
		}
		reverse(str[l:r])
		l = r + 1
		r = r + 1
	}
	return string(str)
}

func reverse(s []byte) {
	l, r := 0, len(s)-1
	for l < r {
		s[l], s[r] = s[r], s[l]
		l++
		r--
	}
	return
}

func trim(s []byte) []byte {
	l, r := 0, len(s)-1
	newstr := []byte{}

	for s[l] == ' ' {
		l++
	}
	for s[r] == ' ' {
		r--
	}

	for l <= r {
		if s[l] != ' ' || (s[l] == ' ' && newstr[len(newstr)-1] != ' ') {
			newstr = append(newstr, s[l])
			l++
		} else {
			l++
		}
	}
	return newstr
}

卡码网：55.右旋转字符串

package main

import "fmt"

func main() {

	var s string
	var n int
	fmt.Scanln(&n)
	fmt.Scanln(&s)
	ss := []byte(s)
	reverseString(ss, n)
	fmt.Printf(string(ss))
}

func reverseString(s []byte, n int) {
	reverse(s)
	reverse(s[:n])
	reverse(s[n:])
}

func reverse(s []byte) {
	l, r := 0, len(s)-1
	for l < r {
		s[l], s[r] = s[r], s[l]
		l++
		r--
	}
}

总结

go语言基础知识欠缺,学习常用库函数