迪拜。哈利法塔原名迪拜塔,又称迪拜大厦或比斯迪拜塔,是世界第一高楼与人工构造物。哈利法塔高828米,楼层总数162层,造价15亿美元,大厦本身的修建耗资至少10亿美元,还不包括其内部大型购物中心、湖泊和稍矮的塔
I have a question about alg开发者_开发问答orithm: How to find all characters in a string whose appearance is greater than a specific number, say 2 for example efficiently?