#246 Search in Rotated Sorted Array

Author: forest000014

search-in-rotated-sorted-array/forest000014.java

@@ -0,0 +1,44 @@
+/*
+# Time Complexity : O(nlogn)
+# Space Complexity : O(1)
+*/
+
+class Solution {
+    public int search(int[] nums, int target) {
+        if (nums[0] == target) return 0;
+        boolean prev;
+        if (nums[0] < target) prev = true;
+        else prev = false;
+
+        int l, r, m, pivot = nums.length - 1;
+        l = 0;
+        r = nums.length - 1;
+        while (l <= r) {
+            m = (r - l) / 2 + l;
+            if (m == nums.length - 1 || nums[m] > nums[m + 1]) {
+                pivot = m;
+                break;
+            } else if (nums[0] <= nums[m]) {
+                l = m + 1;
+            } else {
+                r = m - 1;
+            }
+        }
+
+        if (prev) {
+            l = 0;
+            r = pivot;
+        } else {
+            l = pivot + 1;
+            r = nums.length - 1;
+        }
+
+        while (l <= r) {
+            m = (r - l) / 2 + l;
+            if (nums[m] == target) return m;
+            else if (nums[m] < target) l = m + 1;
+            else r = m - 1;
+        }
+        return -1;
+    }
+}