Ребят кто шарит очень Задание 3-10

на С++ как то так

#include<iostream>
#include<ctime>

using namespace std;

int main(){
srand(time(NULL));
int N, a, sum = 0, ten = 10, index = 0;
int *arr;
cout << "enter size of arr(enter N) : ";
cin >> N;
arr = new int [N];

for(int i = 1; i <= N;i++)
arr[i] = rand()%25;

cout << "arr : " << endl;
for(int i = 1; i <= N;i++)
cout << arr[i] << " " ;
cout << endl;

cout << "enter a : " ;
cin >> a;

for(int i = 1; i <= N;i++)
{
if(arr[i] == a)
index = i;

}
if(index != 0)
{
for(int i = index + 1; i <= N;i++)
sum = sum + arr[i];
}
if(sum == 0)
cout << "Result = " << ten << endl;
else
cout << "Result = " << sum << endl;
}