Add find-minimum-in-rotated-sorted-array solution

Author: Jeehay28

find-minimum-in-rotated-sorted-array/Jeehay28.js

@@ -0,0 +1,49 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+
+// Binary Search
+// Time Complexity: O(log n) (Binary search halving the search space each step)
+// Space Complexity: O(1) (No extra space except for a few variables)
+var findMin = function (nums) {
+  // Example Rotations:
+  // nums = [0,1,2,4,5,6,7]
+  // [4,5,6,7,0,1,2] -> Rotated 4 times
+  // [0,1,2,4,5,6,7] -> 7 times rotated
+
+  // Initial State:
+  // [4, 5, 6, 7, 0, 1, 2]
+  //  ↑                 ↑
+  // (left)           (right)
+  //
+  // Find mid:
+  // [4, 5, 6, 7, 0, 1, 2]
+  //  ↑       🎯        ↑
+  // (left)   (mid)   (right)
+  //
+  // If nums[mid] > nums[right], move left to search in the right half:
+  // [4, 5, 6, 7, 0, 1, 2]
+  //              ↑     ↑
+  //          (left)   (right)
+
+  let left = 0;
+  let right = nums.length - 1;
+
+  while (left < right) {
+    let mid = Math.floor((left + right) / 2);
+
+    if (nums[mid] > nums[right]) {
+      // Minimum must be in the right half
+      // Need to update left to search in the right half
+      left = mid + 1;
+    } else {
+      // Minimum is in the left half (including mid)
+      // Need to update right to search in the left half
+      right = mid;
+    }
+  }
+
+  return nums[left];
+};
+