https://www.lanqiao.cn/problems/497/learning/
解法:暴力
注意:最后得到的平均值要保留两位小数,是double型,所以sum要强转为double型
https://www.lanqiao.cn/problems/541/learning/
解法:暴力
https://www.lanqiao.cn/problems/548/learning/
解法:暴力
https://www.lanqiao.cn/problems/549/learning/
解法:暴力
https://www.lanqiao.cn/problems/1590/learning/
解法:运用字符串方法
https://www.lanqiao.cn/problems/325/learning/
解法:暴力