剑指offer相关题目2：删除字符串中所有重复出现的字符 0(n)

#相关题目2：删除字符串中所有重复出现的字符 0(n)
def deleteRepeatStr(str):
    dict={}
    for i in str:
        if i in dict:
            dict[i]+=1
        else:
            dict[i]=1
    print(dict)
    res=[]
    for i in str:
        if dict[i]>1:
            res.append(i)
            dict[i]-=500
        elif dict[i]==1:
            res.append(i)
    print(res)
    return ''.join(res)
            
    
str='google'
deleteRepeatStr(str)

a='google'
def deleteRepeatStr(str):
    a_1 = ""
    for i in str:
        if i not in a_1:
            a_1 += i
    return a_1
deleteRepeatStr(a)