luojiyin1987

# Definition for singly-linked list.
# class ListNode:
#     def __init__(self, x):
#         self.val = x
#         self.next = None

class Solution:
    def reverseList(self, head):
        """
        :type head: ListNode

luojiyin1987

class Solution:
    def mostCommonWord(self, paragraph, banned):
        """
        :type paragraph: str
        :type banned: List[str]
        :rtype: str
        """
        p = re.compile(r"[!?',;.]")
        paraStrs = p.sub('', paragraph.lower()).split(' ')
      

luojiyin1987

func romanToInt(s string) int {
    numbers := map[string]int{"M":1000, "D":500, "C":100, "L":50, "X":10, "V":5, "I":1}
    last  := -1
    sum := 0
    
    bytes  := []byte(s)
    
    for i := range bytes{
        if last > 0  &&  numbers[string(bytes[i])] > last {
            sum -= 2 * last

luojiyin1987

class Solution:
    def romanToInt(self, s):
        """
        :type s: str
        :rtype: int
        """
        sum  = 0
        last = None
        numbers = {"M":1000, "D":500, "C":100, "L":50, "X":10, "V":5, "I":1}
        

luojiyin1987

func lemonadeChange(bills []int) bool {
    numFive :=0
    numTen :=0
    numTwenty :=0
    
    for i := range bills {
        switch bills[i] {
            case 5: 
                numFive +=1
            case 10 :

luojiyin1987

class Solution:
    def lemonadeChange(self, bills):
        """
        :type bills: List[int]
        :rtype: bool
        """
        numFive = 0
        numTen = 0
        numTwenty = 0 
        

luojiyin1987

func rotateString(A string, B string) bool {
    if len(A) != len(B) {
        return false
    } else if (len(A) == 0  && len(B)==0) {
        return true
    }
    
    bytes := []byte(A)
    l := len(bytes)
    

luojiyin1987

class Solution:
    def countBinarySubstrings(self, s):
        """
        :type s: str
        :rtype: int
        """
        size = len(s)
        cnt = [0, 0]
        last = None
        ans = 0

luojiyin1987

func countBinarySubstrings(s string) int {
    count, countZero, countOne := 0, 0, 0
	prev := rune(s[0])

	for _, r := range s {
		if prev == r {
			if r == '0' {
				countZero++
			} else {
				countOne++

luojiyin1987

func rotatedDigits(N int) int {
    count := 0 
    for i :=2; i <= N; i++ {
        if isValid(i) {
            count++
        }
    }
    return count
}