// CSC 240 - Diagnostic Q2 - Array processing (CSC 142, arrays)
// For a = {4, 9, 7, 2, 9, 5}: sum, average, max, min, their indices, even-index sum.
public class Q2_ArrayProcessing {
    public static void main(String[] args) {
        double[] a = {4.0, 9.0, 7.0, 2.0, 9.0, 5.0};

        double sum = 0;
        double max = a[0];  int maxIdx = 0;   // start from element 0, not from 0.0
        double min = a[0];  int minIdx = 0;
        double evenIndexSum = 0;

        for (int i = 0; i < a.length; i++) {  // i < length (NOT <=)
            sum += a[i];
            if (a[i] > max) { max = a[i]; maxIdx = i; }   // track the INDEX too
            if (a[i] < min) { min = a[i]; minIdx = i; }
            if (i % 2 == 0) evenIndexSum += a[i];         // even INDEX: 0,2,4
        }
        double avg = sum / a.length;

        System.out.println("sum          = " + sum);           // 36.0
        System.out.println("average      = " + avg);           // 6.0
        System.out.println("max          = " + max + " at index " + maxIdx); // 9.0 at 1
        System.out.println("min          = " + min + " at index " + minIdx); // 2.0 at 3
        System.out.println("even-index sum = " + evenIndexSum);// 20.0 (4+7+9)
        // Note: "index of max" is the FIRST max (index 1). Deciding first-vs-last
        // on ties is a design choice - here we keep the first because we use ">".
    }
}