[LeetCode] 165. Compare Version Numbers

思路:
拿俩指针遍历两个字符串, 遇到’.’就停然后向后挪一位进行atoi取值. 如果版本数字少的字符串先被遍历完了以后就用0代替一下. 0ms.

int compareVersion(string version1, string version2) {
    int i = 0, j = 0;
    int n1, n2;

    while (i < version1.length() || j < version2.length()) {
        n1 = i < version1.length() ? atoi(version1.c_str() + i) : 0;
        n2 = j < version2.length() ? atoi(version2.c_str() + j) : 0;

        if (n1 < n2)
            return -1;
        if (n1 > n2)
            return 1;

        while (i < version1.length() && version1[i] != '.')
            i++;
        while (j < version2.length() && version2[j] != '.')
            j++;
        i++;
        j++;
    }

    return 0;
}