Python 判断子序列

s = "abc"

t = "ahbgdc"

class Solution: (error)

    def isSubsequence(self, s: str, t: str):

        for i in range(len(s)):

            if  s[i] in t:

                if i <= t.index(s[i]) :

                   return  s;

                else:

                    return false

class Solution2:(error)
def isSubsequence(self, s: str, t: str) -> bool:
for i in range(len(s)):
if s[i] in t:
if i < len(s)-1 :
# if t.index(s[i]) <= t.index(s[i+1]):
if t.index(s[i]) < t.index(s[1+i]):
if i== len(s)-2 :
print("run here")
return True
else:
print("error")
return False
return False

 

class Solution3:(ture)

    def isSubsequence(self, s: str, t: str) -> bool:

        m,n = len(s),len(t)

        k,l=0,0

        while  k < m and  l <  n :

            if s[k] == t[l]:

                k+=1

            l+=1

        if k== m:

            return True

        else:

            return False