array

1. initial

// https://en.cppreference.com/w/c/language/array_initialization

2. get max or min element

// array
int a[6] = { 1, 45, 54, 71, 76, 12 };
auto b = *max_element(a, a+6);
auto c = *min_element(a, a+6);

// vector
vector<int> a = { 1, 45, 54, 71, 76, 12 };
auto b = *max_element(a.begin(), a.end());
auto c = *min_element(a.begin(), a.end());

3. get size of array

int arr[5] = {10, 20, 30, 40, 50};
// Approach 1
int arrSize = sizeof(arr) / sizeof(arr[0]);
// Approach 2
int arrSize = *(&arr + 1) - arr;

4. get sum

Using Accumulate Method
The accumulate method in c++ used to find the array sum. This function can be accessed from the numeric library in c++.

// array
#include <numeric>
int arr[] = { 1, 5};
int n = 2, initial_sum = 0; sum = 0;
sum = accumulate(arr, arr+n, initial_sum);  // n=0 sum=0; n=1 sum=1; n=2 sum=6

// vector
#include <numeric>
vector<int> v{1, 2, 3};
int initial_sum = 0, sum = 0;
sum = accumulate(v.begin(), v.begin() + 1, initial_sum);  // sum = 1