-
Notifications
You must be signed in to change notification settings - Fork 2
/
RotateSearch.java
113 lines (97 loc) · 3.65 KB
/
RotateSearch.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
/*
* Copyright [2017] [Haibo(Tristan) Yan]
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.haibo.yan.algorithm.binarysearch;
class RotateSearch {
public int search1(int[] nums, int target) {
if (nums == null || nums.length == 0)
return -1;
return search1(nums, target, 0, nums.length - 1);
}
private int search1(int[] nums, int target, int left, int right) {
while (left <= right) {
int medium = (left + right) / 2;
if (target == nums[medium]) {
return medium;
} else if (nums[left] <= nums[medium]) {
if (target < nums[medium] && target >= nums[left]) {
return search1(nums, target, left, medium - 1);
} else {
return search1(nums, target, medium + 1, right);
}
} else {
if (target > nums[medium] && target <= nums[right]) {
return search1(nums, target, medium + 1, right);
} else {
return search1(nums, target, left, medium - 1);
}
}
}
return -1;
}
public int search2(int[] nums, int target) {
if (nums == null || nums.length == 0)
return -1;
return search2(nums, target, 0, nums.length - 1);
}
private int search2(int[] nums,int target, int s, int e) {
System.out.printf("s = %d, e = %d\n", s, e);
if (s > e)
return -1;
int m = (s + e) / 2;
if (nums[m] == target) {
return m;
} else if (nums[m] > target) {
if (nums[s] < nums[m] && target >= nums[s] || nums[s] > nums[m]) {
return search2(nums,target, s, m - 1);
} else {
return search2(nums,target, m + 1, e);
}
} else {
if (nums[m] < nums[e] && target <= nums[e] || nums[m] > nums[e]) {
return search2(nums,target, m + 1, e);
} else {
return search2(nums,target, s, m - 1);
}
}
}
public boolean isInList(int[] nums, int target) {
if (nums == null || nums.length == 0)
return false;
return isInList(nums, target, 0, nums.length - 1);
}
private boolean isInList(int[] nums,int target, int s, int e) {
if (s > e)
return false;
int m = (s + e) / 2;
if (nums[m] == target) {
return true;
} else if (nums[s] == nums[m] && nums[e] == nums[m]) {
return isInList(nums, target, s, m - 1) || isInList(nums, target, m + 1, e);
} else if (nums[m] > target) {
if (nums[s] < nums[m] && target >= nums[s] || nums[s] > nums[m]) {
return isInList(nums, target, s, m - 1);
} else {
return isInList(nums, target, m + 1, e);
}
} else {
if (nums[m] < nums[e] && target <= nums[e] || nums[m] > nums[e]) {
return isInList(nums, target, m + 1, e);
} else {
return isInList(nums, target, s, m - 1);
}
}
}
}