From 0cec6b87463123fdd7aef9ae73af852033b77c0a Mon Sep 17 00:00:00 2001 From: Buay Dak Date: Wed, 15 Apr 2026 23:50:03 -0700 Subject: [PATCH] Finshed time complexity assignment --- src/Main.java | 53 +++++++++++++++++++++++++++++++-------------------- 1 file changed, 32 insertions(+), 21 deletions(-) diff --git a/src/Main.java b/src/Main.java index 036c766..6431e9d 100644 --- a/src/Main.java +++ b/src/Main.java @@ -1,12 +1,13 @@ import java.util.ArrayList; import java.util.HashMap; import java.util.HashSet; +import java.util.Map; import java.util.Set; public class Main { // The time complexity is: - // YOUR ANSWER HERE + // YOUR ANSWER HERE O(n^2) to X public static void timesTable(int x) { for(int i = 1; i <= x; i++) { for(int j = 1; j <= x; j++) { @@ -17,7 +18,7 @@ public static void timesTable(int x) { } // The time complexity is: - // YOUR ANSWER HERE + // YOUR ANSWER HERE O(n) to letter public static void printLetters(String word) { char[] letters = word.toCharArray(); @@ -27,7 +28,7 @@ public static void printLetters(String word) { } // The time complexity is: - // YOUR ANSWER HERE + // YOUR ANSWER HERE O(n) OF bannedPasswords public static boolean isBanned(String password) { String[] bannedPasswords = {"password", "hello", "qwerty"}; boolean banned = false; @@ -41,7 +42,7 @@ public static boolean isBanned(String password) { // The time complexity is: - // YOUR ANSWER HERE + // YOUR ANSWER HERE O(n) TO nums array public static int computeProduct(int[] nums) { int total = 1; for(int num : nums) { @@ -51,7 +52,7 @@ public static int computeProduct(int[] nums) { } // The time complexity is: - // YOUR ANSWER HERE + // YOUR ANSWER HERE O(1) public static void describeProduct(int[] nums) { System.out.println("About to compute the product of the array..."); int product = computeProduct(nums); @@ -60,7 +61,7 @@ public static void describeProduct(int[] nums) { // The time complexity is: - // YOUR ANSWER HERE + // YOUR ANSWER HERE O(n) public static int computeFactorial(int n) { int result = 1; for(int i = 1; i <= n; i++) { @@ -70,7 +71,7 @@ public static int computeFactorial(int n) { } // Assume that the largest number is no bigger than the length - // of the array + // of the array O(n) public static void computeAllFactorials(int[] nums) { for(int num : nums) { int result = computeFactorial(num); @@ -81,7 +82,7 @@ public static void computeAllFactorials(int[] nums) { // assume that each String is bounded by a constant length // The time complexity is: - // YOUR ANSWER HERE + // YOUR ANSWER HERE O(n) public static void checkIfContainedArrayList(ArrayList arr, String target) { if (arr.contains(target)) { System.out.println(target + " is present in the list"); @@ -94,7 +95,7 @@ public static void checkIfContainedArrayList(ArrayList arr, String targe // assume n = wordsA.length = wordsB.length // assume that each String is bounded by a constant length // The time complexity is: - // YOUR ANSWER HERE + // YOUR ANSWER HERE O(n^2) public static boolean containsOverlap(String[] wordsA, String[] wordsB) { for(String wordA : wordsA) { for(String wordB : wordsB) { @@ -108,7 +109,7 @@ public static boolean containsOverlap(String[] wordsA, String[] wordsB) { // assume that each String is bounded by a constant length // The time complexity is: - // YOUR ANSWER HERE + // YOUR ANSWER HERE O(n) public static boolean containsOverlap2(String[] wordsA, String[] wordsB) { Set wordsSet = new HashSet<>(); for(String word : wordsA) { @@ -125,7 +126,7 @@ public static boolean containsOverlap2(String[] wordsA, String[] wordsB) { } // The time complexity is: - // YOUR ANSWER HERE + // YOUR ANSWER HERE O(n) public static void printCharacters(char[] chars) { for (int i = 0; i < chars.length; i++) { char character = chars[i]; @@ -133,14 +134,14 @@ public static void printCharacters(char[] chars) { } } // The time complexity is: - // YOUR ANSWER HERE + // YOUR ANSWER HERE o(1) public static double computeAverage(double a, double b) { return (a + b) / 2.0; } // assume that each String is bounded by a constant length // The time complexity is: - // YOUR ANSWER HERE + // YOUR ANSWER HERE O(1) public static void checkIfContainedHashSet(HashSet set, String target) { if (set.contains(target)) { @@ -156,7 +157,7 @@ public static void checkIfContainedHashSet(HashSet set, String target) // Otherwise, it returns "Person not found" // assume that each String is bounded by a constant length // What is the time complexity of this method? - // YOUR ANSWER HERE + // YOUR ANSWER HERE O(n) public static String emailLookup(String[] names, String[] emails, String queryName) { for(int i = 0; i < names.length; i++) { if (names[i].equals(queryName)) { @@ -172,15 +173,18 @@ public static String emailLookup(String[] names, String[] emails, String queryNa // Write this method to efficiently return the corresponding email or "Person not found" if appropriate // assume that each String is bounded by a constant length // What is the time complexity of your solution? - // YOUR ANSWER HERE + // YOUR ANSWER HERE O(1) public static String emailLookupEfficient(HashMap namesToEmails, String queryName) { - return null; + if (namesToEmails.containsKey(queryName)) { + return namesToEmails.get(queryName); + } + return "Person not found"; } // What is the time complexity of this method? // assume that each String is bounded by a constant length // (assume the set and list have the same number of elements) - // YOUR ANSWER HERE + // YOUR ANSWER HERE O(n^2) public static boolean hasCommon(HashSet wordSet, ArrayList wordList) { for(String word : wordSet) { if(wordList.contains(word)) { @@ -193,24 +197,31 @@ public static boolean hasCommon(HashSet wordSet, ArrayList wordL // Do not change the datatype of wordSet or wordList. // assume that each String is bounded by a constant length // What is the time complexity of your new solution? - // YOUR ANSWER HERE + // YOUR ANSWER HERE O(n) public static boolean hasCommonEfficient(HashSet wordSet, ArrayList wordList) { + for (String word : wordList) { + if (wordSet.contains(word)) { + return true; + } + } return false; } + + // Suppose you are building a dashboard that displays real-time stock prices. // You want to keep track of the current price of each stock, with the stock's ticker symbol as the key. // The prices will be updated frequently throughout the day, and you need to efficiently update // and access the current price for each stock. The order of the ticker symbols is not important. // What would be a good choice of data structure? - // YOUR ANSWER HERE + // YOUR ANSWER HERE Hashmap // Suppose you are building a music player application where users can create playlists. // Songs can be added to the end of the playlist in the order the user chooses, and the user can // skip to the next or previous song. Most operations involve adding songs and accessing them by // their position in the playlist. // What would be a good choice of data structure? - // YOUR ANSWER HERE + // YOUR ANSWER HERE Arraylist // Suppose you are developing a search feature that keeps track of the user's // recent search queries. You want to store the queries in the order they were made, @@ -218,5 +229,5 @@ public static boolean hasCommonEfficient(HashSet wordSet, ArrayList