0001~0010

/**
 * @param a: An integer
 * @param b: An integer
 * @return: The sum of a and b 
 */
func Aplusb(a int, b int) int {
    // write your code here
    return a + b
}

/**
 * @param k: An integer
 * @param n: An integer
 * @return: An integer denote the count of digit k in 1..n
 */
import (
    "strconv"
    "strings"
)
func DigitCounts(k int, n int) int {
    // write your code here
    //思路：0-n转换为字符串切片
    src := ""
    target := strconv.Itoa(k)
    //把0-n的数字转化为字符串添加到切片当中
    for i := 0; i <= n; i++ {
        src += strconv.Itoa(i)
    }
    //查找对应出现的次数
    return strings.Count(src, target)
}

import (
    "bytes"
    "strconv"
    "strings"
)
func DigitCounts(k int, n int) int {
    // write your code here
    var strs string
    var buffer bytes.Buffer
    for i := 0; i <= n; i++ {
        buffer.WriteString(strconv.Itoa(i))
    }
    strs = buffer.String()
    return strings.Count(strs, strconv.Itoa(k))
}

0011~0020

/**
 * @param source: 
 * @param target: 
 * @return: return the index
 */
import "strings"
func StrStr(source string, target string) int {
    // Write your code here
    return strings.Index(source,target)
}

/**
 * @param nums: The integer array.
 * @param target: Target to find.
 * @return: The first position of target. Position starts from 0.
 */
func BinarySearch(nums []int, target int) int {
    // write your code here
    l,r := 0,len(nums)-1
    m := l + (r - l) >> 1
    for l + 1 < r{
        //这边必须是target > nums[m]
        if target > nums[m]{
            l = m
        }else {
            r = m
        }
        m = l + (r - l) >> 1
    }
    if nums[l] == target {
        return l
    }
    if nums[r] == target {
        return r
    }
    return -1
}

0021~0030

/**
 * @param c: A character.
 * @return: The character is alphanumeric or not.
 */
func IsAlphanumeric(c byte) bool {
    // write your code here
    if c <= 'z' && c >= 'a' || c <= 'Z' && c >= 'A' || c <= '9' && c >= '0'{
        return true
    }
    return false
}

0031~0040

/**
 * @param number: A 3-digit number.
 * @return: Reversed number.
 */
func ReverseInteger(number int) int {
    // write your code here
    i := number % 10
    j := number / 10 % 10
    k := number / 100
    return i * 100 + j * 10 + k
}

0041~0050