Return Index of the Smallest Value in a Vector

Return index of the smallest value in a vector?

You're looking for which.min():

a <- c(1,2,0,3,7,0,0,0)
which.min(a)
# [1] 3

which(a == min(a))
# [1] 3 6 7 8

(As you can see from the above, when several elements are tied for the minimum, which.min() only returns the index of the first one. You can use the second construct if you instead want the indices of all elements that match the minimum value.)

How to get the index of the smallest element in a vector?

You can also do this:

std::vector<int>::iterator it = std::min_element(std::begin(vec), std::end(vec));
std::cout << "index of smallest element: " << std::distance(std::begin(vec), it);

or even simpler:

auto it = std::min_element(std::begin(vec), std::end(vec));
std::cout << "index of smallest element: " << std::distance(std::begin(vec), it);

or:

std::cout << "index of smallest element: " <<
std::distance(std::begin(v), std::min_element(std::begin(v), std::end(v)))

How to get the index of the minimum value of an array

Base are

which(centopulos==min(centopulos))

But maybe there is a more fancy way

C++ retrieving an index value in a vector while using min_element or max_element

std::min_element() and std::max_element() work with iterators, not indexes.

For an indexable container like std::vector, you can convert an iterator to an index using std::distance(), eg:

std::string getTopEmployee( const std::vector<std::string>& names, const std::vector<unsigned>& ratings ) {
    // Find Largest Value in ratings
    auto largest = std::max_element( ratings.begin(), ratings.end() );
    if (largest == ratings.end()) return "";
    return names[std::distance(ratings.begin(), largest)];
}

std::string getWorstEmployee( const std::vector<std::string>& names, const std::vector<unsigned>& ratings ) {
    // Find Smallest Value in ratings
    auto smallest = std::min_element( ratings.begin(), ratings.end() );
    if (smallest == ratings.end()) return "";
    return names[std::distance(ratings.begin(), smallest)];
}

How to find the vector element that indexes the lowest value in an array

This is taken straight from http://en.cppreference.com/w/cpp/algorithm/min_element

If i understand correctly you want to get the index of the minimal element in an array

This should work both with vectors and arrays alike

std::vector<int> v{3, 1, 4, 1, 5, 9};

// We need to get the min value
std::vector<int>::iterator result = std::min_element(std::begin(v), std::end(v));
// Then we get the index of the value in the array
std::cout << "min element at: " << std::distance(std::begin(v), result);

What you can do is first get all the values of Cost array in the position of id values and store them in an temporary std::vector.

According to your code, you can use a iterator over the values contained in ids, inside the loop you use std::vector push_back() function to add the elements in position of Cost[id].

Then apply the above mentioned std::min_element and std::distance to get the index. Note that this will return the index of the id vector, getting the value from there is just a matter of ids[index]

Julia Questions: Find n-smallest value's index in vector

Use partialsortperm:

julia> partialsortperm([1, 5, 6, 7, 8, 9, 10, 2, 3, 4], 1:5)
5-element view(::Vector{Int64}, 1:5) with eltype Int64:
  1
  8
  9
 10
  2

julia> partialsortperm([1, 8, 6, 7, 8, 9, 10, 2, 3, 4], 1:5)
5-element view(::Vector{Int64}, 1:5) with eltype Int64:
  1
  8
  9
 10
  3

How can I find the index of the smallest member of this vector in Clojure?

user=> (first (apply min-key second (map-indexed vector [1 2 4 0 5])))
3

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