Follow up for "Search in Rotated Sorted Array":
What if duplicates are allowed?
Would this affect the run-time complexity? How and why?
Write a function to determine if a given target is in the array.
public class Solution {
public boolean search(int[] arr, int target) {
if(arr.length==1&&arr[0]==target){
return true;
}
int left=0;int right=arr.length-1;
int mid=0;
while(left<=right){
mid=(left+right)/2;
if(target==arr[mid]||target==arr[left]||target==arr[right]){
return true;
}
if(arr[left]<arr[right]){ //正常序列
if(target<arr[left]||target>arr[right]){
return false;
}
if(target<arr[mid]){
right=mid-1;
}else{
left=mid+1;
}
}else if(arr[left]>arr[right]){ //旋转序列
if(arr[mid]>=arr[left]){
if(arr[mid]>target){
if(target>arr[left]){
right=mid-1;
}else{
left=mid+1;
}
}else{
left=mid+1;
}
}else{
if(arr[mid]>target){
right=mid-1;
}else{
if(arr[left]>target){
left=mid+1;
}else{
right=mid-1;
}
}
}
}else{ //左右一样大
for(int i=left;i<right;i++){
if(arr[i]==target){
return true;
}
}
return false;
}
}
return false;
}
}