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SearchInRotatedArray.java
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84 lines (72 loc) · 2.18 KB
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package Algorithms;
public class SearchInRotatedArray {
public static void main(String[] args) {
SearchInRotatedArray sa = new SearchInRotatedArray();
int A[] = {3,1,1};
sa.search2(A, 3);
}
public int search(int[] A, int target) {
if (A == null || A.length == 0) {
return 0;
}
int low = 0;
int up = A.length - 1;
int mid;
while (true) {
if (low > up) {
return -1;
}
mid = low + (up - low) / 2;
if (A[mid] == target) {
return mid;
}
if (A[low] < A[mid]) {
// the left side is sorted.
if (A[mid] > target && A[low] < target) {
// target is in the sorted side.
up = mid - 1;
} else {
low = mid + 1;
}
} else {
// the right side is sorted.
if (A[up] > target && A[mid] < target) {
// target is in the sorted side.
low = mid + 1;
} else {
up = mid - 1;
}
}
}
}
public boolean search2(int[] A, int target) {
if (A == null || A.length == 0) {
return false;
}
int l = 0;
int r = A.length - 1;
int mid;
while (l <= r) {
mid = l + (r - l)/2;
if (A[mid] == target) {
return true;
}
if (A[mid] > A[l]) { // left side is sorted.
if (target >= A[l] && target < A[mid]) {
r = mid - 1;
} else {
l = mid + 1;
}
} else if (A[mid] < A[r]) { // right side is sorted.
if (target > A[mid] && target <= A[r]) {
l = mid + 1;
} else {
r = mid - 1;
}
} else {
l++;
}
}
return false;
}
}