*

coding_interviews/algoexpert/longest-peak/longest-peak.js

@@ -0,0 +1,35 @@
+// Runtime: O(N)
+// Space: O(1)
+
+function longestPeak(array) {
+  let longestPeak = 0;
+  let leftEdge;
+  let rightEdge;
+
+  for (let peakIndex = 1; peakIndex < array.length - 1; peakIndex++) {
+    if (
+      array[peakIndex] > array[peakIndex - 1] &&
+      array[peakIndex] > array[peakIndex + 1]
+    ) {
+      for (let index = peakIndex; index > 0; index--) {
+        if (array[index - 1] < array[index]) {
+          leftEdge = index - 1;
+        } else {
+          break;
+        }
+      }
+
+      for (let index = peakIndex; index < array.length - 1; index++) {
+        if (array[index] > array[index + 1]) {
+          rightEdge = index + 1;
+        } else {
+          break;
+        }
+      }
+
+      longestPeak = Math.max(longestPeak, rightEdge - leftEdge + 1);
+    }
+  }
+
+  return longestPeak;
+}