Let's call an array A
a mountain if the following properties hold:
A.length >= 3
- There exists some
0 < i < A.length - 1
such thatA[0] < A[1] < ... A[i-1] < A[i] > A[i+1] > ... > A[A.length - 1]
Given an array that is definitely a mountain, return any i
such that A[0] < A[1] < ... A[i-1] < A[i] > A[i+1] > ... > A[A.length - 1]
.
Example 1:
Input: [0,1,0] Output: 1
Example 2:
Input: [0,2,1,0] Output: 1
Note:
3 <= A.length <= 10000
0 <= A[i] <= 10^6
- A is a mountain, as defined above.
代码如下:
int peakIndexInMountainArray(int* A, int ASize) {
int i,j;
for(i=1;i<ASize-1;i++)
if(A[i]<A[i-1])
break;
j=i-1;
return j;
}