Traversing an Array and Apply a Process (Algorithm 4.1)

Before seeing the solution make sure that you tried enough. Don’t paste the whole code, just find out the logic. If you stuck in trouble, just inform me on comment.

/**Bismillahir Rahmanir Rahim.**/

#include <stdio.h>
int main()
{
    int N, i, k,LB,UB;
    scanf("%d", &N);
    int LA[N];
    for(i=0; i<N; i++) scanf("%d", &LA[i]);
    scanf("%d%d", &LB, &UB);
    for(k=LB; k<=UB; k++) LA[k]+=5;
    for(i=0; i<N; i++) printf("%d\t", LA[i]);
    printf("\n");
    return 0;
}

First input N = array element number. ex.      8
Second input LA[i] = input N element one by one. ex.     3 5 7 9 11 13 15 17
Third input LB = From Which Index I Want to Change. ex.      2
Forth input UB = Till Which Index I Want to Change. ex.       5
I add 5 on every Index from LB to UB.
You can do anything you want by changing a little bit 8-).
Output ex.         3 5 12 14 16 18 15 17