CompareVersionNumber_NO165.java

public class CompareVersionNumber_NO165 {
    public static void main(String[] args){
        System.out.print(new Solution().compareVersion("1.1","1.0"));

    }
    public int compareVersion(String version1,String version2)
    {
        int l1 = version1.length();
        int l2 = version2.length();
        int p1 = 0x00, p2 = 0x00;
        int v1 = 0x00, v2 = 0x00;
        while ( p1 < l1 || p2 < l2)
        {
            //每次取出一个等级的数进行比较
            while (p1 < l1 && version1.charAt(p1) != '.')
            {
                v1 = v1 * 10 + ( version1.charAt(p1) - '0');
                ++p1;
            }
            while (p2 < l2 && version2.charAt(p2) != '.')
            {
                v2 = v2 * 10 + ( version2.charAt(p2) - '0');
                ++p2;
            }
            if (v1 > v2)
                return 1;
            else if (v1 < v2 )
                return -1;
            else{
                v1 = 0x00;
                v2 = 0x00;
                ++p1;
                ++p2;
            }
        }
        return 0;
    }
/*    public int compareVersion(String version1, String version2) {
        String[] v1 = version1.split("\\.");   // 正则表达式,点需要使用反义。
        String[] v2 = version2.split("\\.");

        if(v1.length == 0)
            v1 = new String[]{version1};
        if(v2.length == 0)
            v2 = new String[]{version2};

        int minL = v1.length < v2.length ? v1.length : v2.length;
        int n1,n2,i;
        for(i = 0; i < minL ; ++i){
            n1 = stringToInt(v1[i]);
            n2 = stringToInt(v2[i]);

            if( n1 < n2 )
                return -1;
            else if(n1 > n2)
                return 1;
            else
                continue;
        }

        if(v1.length != minL){
            for(;i< v1.length;++i){
                if(stringToInt(v1[i]) != 0)
                    return 1;
            }
        }else if ( v2.length!= minL){
            for(;i< v2.length;++i){
                if(stringToInt(v2[i]) != 0)
                    return -1;
            }
        }else{
            return 0;
        }
        return 0;

    }
    public int stringToInt(String s){
        int result = 0;
        char[] charArray = s.toCharArray();
        for(char c: charArray){
            result *= 10;
            if( c <= '9' && c >= '0' )
                result += ( c - '0');
            else
                return -1;
        }
        return result;
    }*/

}