feat: Solves Validate Subsequence

  - AlgoExpert

Author: brianr482

arrays-strings/validate-subsequence.js

@@ -0,0 +1,36 @@
+/**
+ * AlgoExpert
+ * 
+ * Given two non-empty arrays of integers, write a function that determines
+ * whether the second array is a subsequence of the first one.
+ * 
+ * A subsequence of an array is a set of numbers that aren't necessarily adjacent
+ * in the array but that are in the same order as they appear in the array. For
+ * instance, the numbers [1, 3, 4] form a subsequence of the array [1, 2, 3, 4],
+ * and so do the numbers [2, 4]. Note that a single number in an array and the
+ * array itself are both valid subsequences of the array.
+ */
+
+/**
+ * @param {number[]} array 
+ * @param {number[]} sequence 
+ * @returns {boolean}
+ */
+function isValidSubsequence(array, sequence) {
+  // Time: O(n), Space: O(1)
+	let seqIdx = 0;
+	let i = 0;
+	
+	while(i < array.length && seqIdx < sequence.length) {
+		const arrElement = array[i];
+		const seqElement = sequence[seqIdx];
+		
+		if (arrElement === seqElement) {
+			seqIdx++;
+		}
+		
+		i++;
+	}
+	
+	return seqIdx === sequence.length;
+}