Find the minimum and maximum of an array with N elements

Question

I need to find min and max of an array with N elements. The fact is that my program is working but when I submit it on a website it gives me only 32 points out of 100 and I don't know what's wrong.

#include <iostream>

using namespace std;

int main() {
    int N,min,max;
    cin >> N;
    min = N;
    max = N;

    int i,x;
    for (i = 1; i <= N; ++i) {
        cin >> x;

        if ( x < min ) {
            min = x;
        }
        if (x > max) {
            max = x;
        }
    }
    cout << min <<" "<< max;
    return 0;
}

Answer 1

Your logic here

min = N;
max = N;

initializing them with N, is wrong. When you have the minimum number for example 0 in your user input, and your N is greater than that 0, you never find your minimum. The same will happen for the maximum.

Initialize min with largest possible value of int and max with least possible value, like the following:

int min = std::numeric_limits<int>::max();
int max = std::numeric_limits<int>::min();

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Suggestion - 1

As it looks like you do not want to save the user input to find mim and max you can use std::min and std::max functions as follows:

#include <iostream>
#include <limits>    //  std::numeric_limits<>
#include <algorithm> //  std::min, std::max

int main()
{
    // initialize like this
    int min = std::numeric_limits<int>::max();
    int max = std::numeric_limits<int>::min();
    int N;
    std::cin >> N;
    while (N--)
    {
        int x; std::cin >> x;
        min = std::min(x, min);  // use std::min
        max = std::max(x, max);  // use std::max
    }
    std::cout << min << " " << max;
    return 0;
}

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Suggestion - 2

If you want to find the min-max of an already existing array, you might wanna consider use std::minmax_element instead.

#include <algorithm>   //  std::minmax_element
#include <iostream>
#include <vector>

int main()
{
    int N; std::cin >> N;
    std::vector<int> v(N);
    for(auto& element: v) std::cin >> element;
    // do something.....

    // to find min-max of the array
    auto result = std::minmax_element(v.begin(), v.end());
    std::cout << "min element is: " << *result.first << '\n';
    std::cout << "max element is: " << *result.second << '\n';
}

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Side Note: Do not practice with std namespüace std;, why? see this post: Why is “using namespace std” considered bad practice?