iterator迭代器进行字母转化，将大写字母转化成小写字母-iterator iterator transformation letters, uppercase letters into lowercase letters

将一组随机的数字分别按照奇偶的特点放置到两个不同的迭代器里面-A set of random numbers, respectively, in accordance with the characteristics of the parity placed inside two different iterator

编写程序来创建有10个元素的vector对象。用迭代器把每个元素值改为当前值的2倍。-Write a program to create vector objects have 10 elements. With the value of each element iterator to 2 times the current value.