distance
求距离
例子:
#include <iostream>
#include <iterator>
#include <vector>
using namespace std;
int main()
{
vector<int> v;
v.push_back(3);
v.push_back(1);
v.push_back(4);
cout << "distance(first, last) = "
<< distance(v.begin(), v.end()) <<endl
<< "distance(last, first) = "
<< distance(v.end(), v.begin()) <<endl;
}
输出:
distance(first, last) = 3
distance(last, first) = -3