C++自定义二分查找

template <typename T>
struct PxMatchEqual {
    bool operator()(T curIndex, T findIndex) const { return curIndex == findIndex; }
};

template <typename T>
struct PxMatchIsLeft {
    bool operator()(T curIndex, T findIndex) const { return findIndex < curIndex; }
};

template <typename Container,
          typename match     = PxMatchEqual<typename Container::value_type>,
          typename canLeft   = PxMatchIsLeft<typename Container::value_type>,
          typename constIter = typename Container::const_iterator,
          typename valType   = typename Container::value_type>
constIter binarySearchRange(constIter left, constIter right, valType index)
{
    if (left > right) {
        return left;
    }
    auto mid    = left;
    auto offset = (right - left) / 2;
    if (0 == offset)
        return left;
    std::advance(mid, offset);

    if (match()(*mid, index)) {
        return mid;
    }
    if (canLeft()(*mid, index)) {
        return binarySearchRange<Container, match, canLeft, constIter>(left, mid, index);
    } else {
        return binarySearchRange<Container, match, canLeft, constIter>(mid, right, index);
    }
}

示例

std::vector<int> indexs{1, 3, 6, 7, 9};
auto begin = indexs.begin();
auto end   = indexs.end();
auto findIndex = 6;
auto findIter =
	BSearch::binarySearchRange<std::vector<int>>(begin, end, findIndex);
if(findIter != end)
	std::cout<< "find\n";

创作不易，小小的支持一下吧！