Address of minimum value in an array in C/C++

Question

Just a week into C/C++. I have a function that takes a pointer to an array as an argument. Manipulating this input array inside the function results in a change in another (globally defined) array. I need to find and return the address of the minimum value in this (globally defined) array of floats. In C++ I can do this relatively easily with std::min_element(), since this returns an iterator. Any way to do this in C? I can write a loop to find the minimum value in an array, but not sure how to access its address? Here'e the (pseduo)code.

globalArray[100] = {0}
float *DoSomething(float *array)
{
    if (conditionMet == 1)
        { Do something to array that modifies globalArray;}
    float min;
    min = globalArray[0];
    for (int i = 0; i <100; i++)
    {
         if (globalArray[i] < min)
            min = globalArray[i];
    }
    return &min;
}

Without some code it is hard to tell what you are asking, but isn't it just return &array[minIndex]; ? — John3136
– John3136, Commented Aug 7, 2017 at 23:58
A week into two different languages at once? Wow. Personally, I'd pick one. — aschepler
– aschepler, Commented Aug 8, 2017 at 0:01
C and C++, despite their superficial similarities, are very, very different languages. Don't confuse the two. — Alex Huszagh
– Alex Huszagh, Commented Aug 8, 2017 at 0:07
Totally understand that C and C++ are different. As I said, I have some sense for how to accomplish this in C++ using std::min_element. But also need to do this in C. — deserthiker
– deserthiker, Commented Aug 8, 2017 at 0:17

merlin2011 · Accepted Answer · 2017-08-08 00:23:04Z

4

You need to keep an extra variable around to track the index.

min = globalArray[0];
int minIndex = 0;
for (int i = 0; i <100; i++)
{
     if (globalArray[i] < min) {
        min = globalArray[i];
        minIndex = i;
     }
}
return &globalArray[minIndex];

Alternatively, you can use the extra variable to track the pointer.

min = globalArray[0];
float* minPointer = globalArray;
for (int i = 0; i <100; i++)
{
     if (globalArray[i] < min) {
        min = globalArray[i];
        minPointer = globalArray + i;
     }
}
return minPointer;

answered Aug 8, 2017 at 0:23

merlin2011

76.5k48 gold badges218 silver badges364 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Address of minimum value in an array in C/C++

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related