因为涉及到将字符串分为单词,用istringstream类来实现的 【1】https://blog.youkuaiyun.com/sunshineacm/article/details/78068987 【2】https://blog.youkuaiyun.com/shs1992shs/article/details/83051298 【3】https://blog.youkuaiyun.com/xiaogugood/article/details/21447431