week 7 in c

<1> Array Reversal

Input Format
The first line contains an integer, , denoting the size of the array. The next line contains  space-separated integers denoting the elements of the array.

Output Format
the output is handled by the code given in the editor, which would print the array.

Sample Input 0
6
16 13 7 2 1 12 

Sample Output 0
12 1 2 7 13 16 

Sample Input 1
7
1 13 15 20 12 13 2

Sample Output 1
2 13 12 20 15 13 1 

Sample Input 2
8
15 5 16 15 17 11 5 11 

Sample Output 2
11 5 11 17 15 16 5 15 

#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>

int main() {

    int i,n;
    long long a[100];
    scanf("%d",&n);
    for(i=1;i<=n;i++)
    {
        scanf("%lld",&a[i]);
    }
    for(i=n;i!=0;i--)
    {
        printf("%lld ",a[i]);
    }
    
    
    
    
<2> Sum of array elements

Input Format
The first line contains an integer, . The next line contains space-separated integers.

Constraints
1 <= n <= 1000 1 <= a[i] <= 1000

Output Format
Print the sum of the integers in the array.

Sample Input 0
6
16 13 7 2 1 12

Sample Output 0
51

#include <stdio.h>

int main(){
    int n;
    scanf("%d",&n);
    int arr[n];
    for(int arr_i = 0; arr_i < n; arr_i++){
       scanf("%d",&arr[arr_i]);
    }
    int result = 0;
    for(int arr_i = 0; arr_i < n; arr_i++){
       result += arr[arr_i];
    }
    printf("%d", result);
    return 0;
}