Mountain, Part IV: public boolean isMountain(int[] nums). Returns true if the values in the array are ordered as a "mountain"; otherwise returns false. For there to be a mountain, all 3 of the following conditions must hold: (1) There must be a peak. (2) The elements to the left of the peak must appear in increasing order. (3) The elements to the right of the peak must appear in decreasing order. Use the 3 methods that your already wrote: isDecreasing(), isIncreasing(), and getPeakIndex().