Java > AP-1 > sumHeights2 (CodingBat Solution)

Problem:

(A variation on the sumHeights problem.) We have an array of heights, representing the altitude along a walking trail. Given start/end indexes into the array, return the sum of the changes for a walk beginning at the start index and ending at the end index, however increases in height count double. For example, with the heights {5, 3, 6, 7, 2} and start=2, end=4 yields a sum of 1*2 + 5 = 7. The start end end index will both be valid indexes into the array with start <= end.

sumHeights2({5, 3, 6, 7, 2}, 2, 4) → 7
sumHeights2({5, 3, 6, 7, 2}, 0, 1) → 2
sumHeights2({5, 3, 6, 7, 2}, 0, 4) → 15

Solution:

public int sumHeights2(int[] heights, int start, int end) {
    int tmp = 0;
  for (int i = start; i <= end-1; i++) {
    if (heights[i] < heights[i+1]) {
      tmp += 2 * (Math.abs(heights[i] - heights[i+1]));
    }
    else
      tmp += Math.abs(heights[i] - heights[i+1]);
  }
  return tmp;
}