int *curr_val;
int history[5];

curr_val = history; // point to the first element of history

// to get a new element:
*curr_val++ = get_new_value();
// make sure to wrap at the end of the history array
// alternatively, replace the pointer with an index value and access the array through that
if(curr_val > &history + 5) curr_val = history;

// for getting the average sum up all values in the array history
int avg;
avg = 0;
for(int i = 0; i < 5; i++) avg += history[i];
avg /= 5;

// now avg has the average of the last 5 elements, including the value we gathered at the start of this snippet



get_new_value = whatever I want to add, such as data or w/e right? followed by a ()