问题描述
我正在做一个练习,我有一个向量,我正在写一个反向算法,通过使用一个反向和一个正向(正向)迭代器来反转向量的内容。但是,我无法比较迭代器。
I am working on an exercise where I have a vector and I am writing my own reverse algorithm by using a reverse and a normal (forward) iterator to reverse the content of the vector. However, I am not able to compare the iterators.
int vals[] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 0 };
vector<int> numbers(vals, vals + 10);
vector<int>::iterator start = numbers.begin();
vector<int>::reverse_iterator end = numbers.rend();
我有一个先前的算法通过使用两个迭代器逆向向量,能够使用!=运算符在它们之间进行比较。我的猜测是获得底层的指针或索引在向量中彼此,但如何获得指针/索引?
I have a previous algorithm for reversing the vector by using two iterators, however in this task I am not able to compare them using the != operator between them. My guess would be to get the underlying pointers or indexes in the vector with each other but how do I get the pointers/index?
推荐答案
使用: it == rit.base() - 1
。
Do a comparison using the the iterator returned by base()
: it == rit.base() - 1
.
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