一道面试题目

有n个字符的字符串a 然后有两个m长的字符串bc，b中的第一个字符如果在a中出现就用c中的第一个替换，第2345。。。。。个同理

要求:o(n)

以下是 phyton实现
def replaceString(a,b,c):
    letterList = {}
    tmp = 97
    i = 0
    k = 0
    l = 0
    myList = []
    while i < 26:
        letterList.setdefault(chr(tmp))
        letterList[chr(tmp)] = 0
        tmp = tmp + 1 
        i = i + 1
    for j in a:
        letterList[j] = 1
    while k < len(b):
        if letterList[b[k]] == 1:
           myList.append(c[k])
        else:
            myList.append(b[k])
        k = k + 1    
    print a
    print b
    print c
    while l < len(myList):
          print myList[l],
          l = l + 1 
   
        
        

a = "asdfgh"
b = "bgu"
c = "nkm"
replaceString(a,b,c)