C++ feladat

#include <iostream>

using namespace std;

void readData(int *a, int n) {
    for(int i = 0; i < n; ++i) {
        scanf("%i", &a[i]);
    }
}

int calculateSum(int *a, int m) {
    return ((a[0]+a[m-1])*m)/2;
}

int main() {
    int *a;
    int n,m;

    freopen("be.txt", "rt", stdin);

    scanf("%i", &n);
    scanf("%i", &m);

    a = (int*)malloc(n*sizeof(int));
    readData(a,n);

    cout << calculateSum(a,m) << endl;

    free(a);

    return 0;
}