8. String to Integer (atoi)

Posted 2021-02-12 sea-stream

 

def solution(s):
    s=s.strip()
    if(s):
        l=len(s)
        first_n=-1
        b_n=-1
        last_n=-1
        f_n=-1
        for i in range(l):
            if(s[i].isdigit()):
                first_n=i
                continue
            if(not s[i].isdigit()):
                if(s[i]=="."):
                    f_n=1
                    continue
                if(i==0):
                    if(s[i]=="-"):
                        b_n=i
                        continue
                    elif(s[i]=="+"):
                        b_n=i
                        continue
                    else:
                        return 0
                else:
                    if(s[i]=="-"):
                        b_n=i
                        continue
                    elif(s[i]=="+"):
                        b_n=i
                        continue
                last_n=i
                break
        print(first_n,last_n,f_n,b_n)
        if(s[0]=="-"):
            if(first_n==-1):
                return 0
            x=s[b_n:first_n+1]
        elif(s[0]=="+"):
            x=s[b_n:first_n+1]
        else:
            if(last_n==-1):
                x=s[:]
            else:
                x=s[0:last_n]
        if(b_n==0 and first_n==-1 and last_n==-1):
            return 0
        print(f_n)
        if(not f_n==-1):
            if(("-" in s) and (("+") in s)):
                return 0
            print(x)
            x=float(x)
        else:
            x=int(x)
        if(x>2147483647):
            return 0
        elif(x<-2147483647):
            return 0
        else:
            return x
    else:
        return 0
    
s="+-2"
print("k",solution(s))