[Leet] 34. Find First and Last Position of Element in Sorted Array [medium]

Author: hyeonbinHur

허현빈/4주차/260120.js

@@ -0,0 +1,31 @@
+/**
+ * @param {number[]} nums
+ * @param {number} target
+ * @return {number[]}
+ */
+var searchRange = function (nums, target) {
+  const findBound = (isFirst) => {
+    let start = 0;
+    let end = nums.length - 1;
+    let ans = -1;
+
+    while (start <= end) {
+      let m = Math.floor((start + end) / 2);
+      if (nums[m] === target) {
+        ans = m;
+        if (isFirst) {
+          end = m - 1;
+        } else {
+          start = m + 1;
+        }
+      } else if (nums[m] < target) {
+        start = m + 1;
+      } else {
+        end = m - 1;
+      }
+    }
+    return ans;
+  };
+
+  return [findBound(true), findBound(false)];
+};