Suppose a sorted array is rotated at some pivot unknown to you beforehand.
(i.e.,
0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2).
You are given a target value to search. If found in the array return its index, otherwise return -1.
You may assume no duplicate exists in the array.
解题思路：
binary search的变型
public class SearchInRotatedArray {
public int search(int[] A, int target) {
int start = 0, end = A.length - 1;
while(start <= end){
int mid = start + (end - start)/2;
if(A[mid] == target){
return mid;
}
if(A[start] <= A[mid]){
if(target < A[start] || target > A[mid]){
start = mid + 1;
}
else{
end = mid - 1;
}
}
else{
if(target > A[mid] && target < A[start]){
start = mid + 1;
}
else{
end = mid - 1;
}
}
}
return -1;
}
}
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