如何实时获取中间值/ C ++

Question

If I get some values from the keyboard, how can I find the middle value between them in real time?

this is what I have done but without any result :(

float *p=new float;  //p points to the first element
float *my;
std::cin >> my;
vector<float*>V;
V.push_back(my);
std::vector<float*>::iterator it;
p=my;

 while(my){
   it=V.begin()+1;
 }

int M =(*it-p)/2;

delete[] p;

to clarify: The middle in terms of order they were given

Answer 1

If you're trying to find the middle value in a container, it's pretty easy:

#include <iostream>
#include <vector>

int main() {
    std::vector<float> v{1,2,3,4,5};

    // Output:     (1,2,3,4,5)
    //          3       ^ 
    std::cout << v.at(v.size()/2) << std::endl;

    // Now a user provides another value, maybe
    v.push_back(6);

    // Output:     (1,2,3,4,5,6)
    //          4         ^
    std::cout << v.at(v.size()/2) << std::endl;
}

Demo

Your code has... a lot of problems with pointers.

Answer 2

@Lightness explained it perfectly. here's another demo (-1 prints the current middle value, -2 exits)

#include <iostream>
#include <vector>

int main() {
    std::vector<float> values;
    float value;

    while(std::cin >> value) {
        if(value == -1 && values.size() > 0)
            std::cout << "mid = " << values.at(values.size() / 2) << std::endl;
        else if (value == -2)
            break;
        else
            values.push_back(value);
    }
}