c++之find()函数

在数组或者向量中，找到一个数，返回它的下标

#include <iostream>     // std::cout
#include <algorithm>    // std::find
#include <vector>       // std::vector

int main () {
  // using std::find with array and pointer:
  int myints[] = { 10, 20, 30, 40 };
  int * p;

  p = std::find (myints, myints+4, 30);
  if (p != myints+4)
    std::cout << "Element found in myints: " << *p << '
';
  else
    std::cout << "Element not found in myints
";

  // using std::find with vector and iterator:
  std::vector<int> myvector (myints,myints+4);
  std::vector<int>::iterator it;

  it = find (myvector.begin(), myvector.end(), 30);
  if (it != myvector.end())
    std::cout << "Element found in myvector: " << *it << "  " << it - myvector.begin() << '
';
  else
    std::cout << "Element not found in myvector
";

  return 0;
}

备注：需要注意的确定搜索范围时，头部是name, 尾部为name+nums, 不是name + num - 1, 以前在使用std::max()函数时就犯过这样的错误。
疑问：是否存在函数可以指定查找的方向，有时候我希望从尾部开始查找。