Find Peak Element, findpeakelement

Find Peak Element, findpeakelement

• A peak element is an element that is greater than its neighbors.

• Given an input array where num [I] =num [I + 1], find a peak element and return its index.

• The array may contain in multiple peaks, in that case return the index to any one of the peaks is fine.

• You may imagine that num [-1] = num [n] =-∞.

• For example, in array [1, 2, 3, 1], 3 is a peak element and your function shocould return the index number 2.

  This question is a question. Pay attention to the boundary conditions.
  C ++ Code:

class Solution {public:    int findPeakElement(const vector<int> &num) {    if (num.size() == 1)    {        return 0;    }    else if (num.size() == 2)    {        return num[0] > num[1] ? 0 : 1;    }    int i = 1;    for (; i < (num.size()-1); i++)    {        if ((num[i] > num[i - 1]) && (num[i] > num[i + 1])){            return i;        }    }    if ((num[0] > num[1])){        return 0;    }    else if (num[i-1] < num[i])    {        return i;    }    return 0;    }};