33. Search in Rotated Sorted Array

arai60/binary-search/search-in-rotated-sorted-array/answer.md

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+# Title
+
+## STEP1
+
+### 発想
+
+### 想定されるユースケース
+
+### 何が分からなかったか?
+
+* 動かなかった時のコード
+
+```javascript
+const search = function(nums, target) {
+    let left = 0
+    let right = nums.length - 2
+    // loop condition: left <= target <= right, and 2 vars exists on 
+    let rotationIdx = 0
+    while (left < right) {
+        const middle = Math.floor((left + right) / 2)
+        if (nums[middle + 1] < nums[middle]) {
+            rotationIdx = middle + 1
+            break
+        }
+        if (nums[0] < nums[middle]) {
+            left = middle + 1
+            continue
+        }
+        right = middle - 1
+    }
+    if (rotationIdx > 0 && nums[0] <= target) {
+        left = 0
+        right = rotationIdx - 1
+    } else if (rotationIdx > 0 && target < nums[0]) {
+        left = rotationIdx
+        right = nums.length - 1
+    } else {
+        left = 0
+        right = nums.length - 1
+    }
+    while (left < right) {
+        const middle = Math.floor((left + right) / 2)
+        if (nums[middle] < target) {
+            left = middle + 1
+            continue
+        }
+        right = middle
+    }
+    if (nums[left] === target) {
+        return left
+    }
+    return -1
+
+};
+```
+
+```javascript
+const search = function(nums, target) {
+    let left = 0
+    let right = nums.length - 2
+    // loop condition: left <= target <= right, and 1 vars exists on 
+    // break condition: when we find the rotation Index or cannot find the rotation index
+    let rotationIdx = 0
+    while (left <= right) {
+        const middle = Math.floor((left + right) / 2)
+        if (nums[middle + 1] < nums[middle]) {
+            rotationIdx = middle + 1
+            break
+        }
+        if (nums[0] <= nums[middle]) {
+            left = middle + 1
+            continue
+        }
+        right = middle - 1
+    }
+    if (rotationIdx > 0 && nums[0] <= target) {
+        left = 0
+        right = rotationIdx - 1
+    } else if (rotationIdx > 0 && target < nums[0]) {
+        left = rotationIdx
+        right = nums.length - 1
+    } else {
+        left = 0
+        right = nums.length - 1
+    }
+    while (left < right) {
+        const middle = Math.floor((left + right) / 2)
+        if (nums[middle] < target) {
+            left = middle + 1
+            continue
+        }
+        right = middle
+    }
+    if (nums[left] === target) {
+        return left
+    }
+    return -1
+};
+```
+
+## STEP2
+
+```javascript
+```
+
+## STEP3
+
+```javascript
+```
+
+## 感想
+
+### コメント集を読んで
+
+## 他の人のPRを読んで
+
+## その他の方法
+
+### コードの良し悪し
+
+* `*0`
+
+* `*1`
+
+## 調べたこと
+