So this is a question of gfg to find union of two arrays and following is my code:
class GFG {
public static void main (String[] args) {
BufferedReader buff = new BufferedReader(new InputStreamReader(System.in));
try{
int testcase = Integer.parseInt(buff.readLine());
while(testcase-->0) {
String[] input = buff.readLine().split(" ");
int size1 = Integer.parseInt(input[0]);
int size2 = Integer.parseInt(input[1]);
Set<Integer> set = new HashSet<>();
String[] inp1 = buff.readLine().split(" ");
String[] inp2 = buff.readLine().split(" ");
for(int i = 0; i < inp1.length; i++){
set.add(Integer.parseInt(inp1[i]));
}
for(int i = 0; i < inp2.length; i++){
set.add(Integer.parseInt(inp2[i]));
}
System.out.println(set.size());
}
}catch(IOException e){System.out.println(e);}
}
}
The expected time and auxiliary space complexity for this program is given as: O(N+M) where N and M are size of two arrays respectively.
So can anyone tell what is space complexity for above code.I am so confused about the space complexity for this code.
Related
I am trying to use user inputted N lines of N characters to do some operations with. But first I need to know N and another int being inputted. When I define N and the other integer K and then write 5 lines (in this case) of 5 characters each the program runs well. But when I use the represented String a (which I then would split into 2 ints, N and K, not shown here to not complicate things), an error occurs. Even if I now input 6 lines, being the 5 last of 5 characters each, the program gives an error of no line found for the multi function. I don't understand what's the problem, and if I remove the string a and just define N and K the program runs well. What's more surprising, the program runs if I use an interactive console instead of text input and write the terms one by one.
static String [][] vetor (int N) {
Scanner scan = new Scanner(System.in);
String[][] multi = new String [N][N];
for (int i = 0 ; i<N ; i++){
String forest = scan.nextLine();
String[] chars = forest.split("");
for (int k=0; k<N; k++){
multi[i][k]= chars [k];
}
}
return multi;
}
public static void main(String args[]) {
Scanner scan = new Scanner(System.in);
String a = scan.nextLine();
int N = 5;
int K = 5;
String [][] multi = vetor(N);
I've tried many things, but I can't make sense of this. I didn't find any similar questions, but feel free to redirect me to an explanation.
Edit: This is a similar program one can run (with a possible input down (K<= N)) :
import java.util.Scanner;
import java.util.Arrays;
public class Main {
static int[] numerificar() {
Scanner myObj = new Scanner(System.in);
String Input = myObj.nextLine();
String[] Inputs = Input.split(" ", 0);
int size = Inputs.length;
int [] a = new int [size];
for(int i=0; i<size; i++) {
a[i] = Integer.parseInt(Inputs[i]);}
return a;
}
static String [][] vetor (int N) {
Scanner scan = new Scanner(System.in);
String[][] multi = new String [N][N];
for (int i = 0 ; i<N ; i++){
String forest = scan.nextLine();
String[] chars = forest.split("");
for (int k=0; k<N; k++){
multi[i][k]= chars [k];
}
}
return multi;
}
public static void main(String args[]) {
Scanner scan = new Scanner(System.in);
int[] a = numerificar();
int N = a[0];
int K = a[1];
int cadeira = 0;
String [][] multi = vetor(N);
for (int i = 0 ; i<N ; i++){
if (cadeira == 1) {
break;
}
for (int k=0; k<N-K+1; k++){
if (cadeira == 1) {
break;
}else if( multi[i][k].equals(".")){
for (int j=0; j<K; j++){
if(multi[i][k+j].equals( "#")){
k+=j;
break;
} else if (j == K-1) {
cadeira = 1;
}
}
}
}
}
System.out.println(cadeira);
}
}
5 3
.#.##
#####
##...
###..
#####
The output should be 1 in this case.
The problem is you are creating more than one Scanner that reads from System.in. When data is readily available, a Scanner object can read more data than you ask from it. The first Scanner, in the numerificar() method, reads more than the first line, and those lines are not available to the second Scanner, in the vetor() method.
Solution: use just one Scanner object in the whole program.
public class Main {
static Scanner globalScanner = new Scanner(System.in);
static int[] numerificar() {
String Input = globalScanner.nextLine();
String[] Inputs = Input.split(" ", 0);
Can someone tell me why this code is running infinitely? I tried everything to fix it but still can't figure it out. The first half of the code works. But the second half doesn't work.
public static void main(String[] args) throws FileNotFoundException{
Scanner in;
in = new Scanner (new File ("ratings"));
int[] [] ratings = new int [30] [20];
int j = 0;
while (in.hasNextLine()){
for (int i = 0; i < 20; i++){
ratings [j] [i] = in.nextInt();
}
j++;
}
in.close();
for (int i = 0; i < ratings.length; i++){
for (int k = 0; k < ratings[i].length; k++){
System.out.print(ratings [i][k] + "");
}
System.out.println();
}
Scanner in1;
in1 = new Scanner(new File("books"));
String[] books = new String [20];
while (in1.hasNextLine()) {
for (int i = 0; i < books.length; i++){
books [i] = in1.toString();
}
}
in1.close();
}
In the last loop, since the books are string, you probably have a typo and would change the in1.toString to in1.next() or in1.nextLine() depending on your file structure and format:
books [i] = in1.toString(); == e.g => books [i] = in1.nextLine();
Cheers!
Assume that i have 4 grades in testgrades.txt I don't know why this wont work.
public static void main(String[] args) throws FileNotFoundException {
File file1= new File("testgrades.txt");
int cnt = 4;
int[] grades = new int[cnt];
String line1;
for (int i=0; i<cnt; i++) {
Scanner inputFile2 = new Scanner(file1);
line1 = inputFile2.nextLine();
int grades2 = Integer.parseInt(line1);
grades[i] = grades2;
}
System.out.print(grades);
First of all, you should note that arrays in java hold fixed-size elements of the same type.
You can initialize them in one of two ways (not very sure if there are other ways).
//First method
int[] anArray = new int[10];
// Second method
int[] anArray = {1,2,3,4,5,6,7,8,9,10};
In either case, the array is of size 10 elements. Since you are fetching the data from the text file, I'll suggest you count number of lines into a variable and use that value to initialize the array. Then you can use a loop to fill the values this way:
// Assuming you have cnt as your total count of grades.
int[] grades = new int[cnt];
String line1;
for (int 1=0; i<cnt; i++) {
line1 = inputFile2.nextLine();
int grades2 = Integer.parseInt(line1);
grades[i] = grades2;
}
This is coming off my head so let me know if you face any problem.
You can do like this
public static void main(String[] args) throws FileNotFoundException {
// TODO code application logic here
File file= new File("testgrades.txt");
Scanner scan = new Scanner(file);
int arr[] = new int[100];
int i = 0;
do{
String line1 = scan.nextLine();
int grades2 = Integer.parseInt(line1);
arr[i++] = grades2;
}while(scan.hasNextLine());
for(int j = 0; j < i; j++){
System.out.println(arr[j]);
}
}
Say I am using this code to convert a String (containing numbers) to an array of characters, which I want to convert to an array of numbers (int).
(Then I want to do this for another string of numbers, and add the two int arrays to give another int array of their addition.)
What should I do?
import java.util.Scanner;
public class stringHundredDigitArray {
/**
* #param args
*/
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
System.out.print("Enter the number: ");
String num1 = in.nextLine();
char[] num1CharArray = num1.toCharArray();
//for (int i = 0; i < num1CharArray.length; i++){
//System.out.print(" "+num1CharArray[i]);
//}
int[] num1intarray = new int[num1CharArray.length];
for (int i = 0; i < num1CharArray.length; i++){
num1intarray[i] = num1CharArray[i];
}
for (int i = 0; i < num1intarray.length; i++){ //this code prints presumably the ascii values of the number characters, not the numbers themselves. This is the problem.
System.out.print(" "+num1intarray[i]);
}
}
}
I really have to split the string, to preferably an array of additionable data types.
try Character.getNumericValue(char); this:
for (int i = 0; i < num1CharArray.length; i++){
num1intarray[i] = Character.getNumericValue(num1CharArray[i]);
}
Try This :
int[] num1intarray = new int[num1CharArray.length];
for (int i = 0; i < num1CharArray.length; i++)
{
num1intarray[i]=Integer.parseInt(""+num1CharArray[i]);
System.out.print(num1intarray[i]);
}
Short and simple solution!
int[] result = new int[charArray.length];
Arrays.setAll(result, i -> Character.getNumericValue(charArray[i]));
I am solving this question.
This is my code:
import java.io.IOException;
import java.util.Scanner;
public class Main {
public static void main(String[] args) throws IOException {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int k = sc.nextInt();
int[] t = new int[n];
int count = 0;
for (int i = 0; i < n; i++) {
t[i] = sc.nextInt();
if (t[i] % k == 0) {
count++;
}
}
System.out.println(count);
}
}
But when I submit it, it get's timed out. Please help me optimize this to as much as is possible.
Example
Input:
7 3
1
51
966369
7
9
999996
11
Output:
4
They say :
You are expected to be able to process
at least 2.5MB of input data per
second at runtime.
Modified CODE
Thank you all...I modified my code and it worked...here it is....
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
String[] input = br.readLine().split(" ");
int n = Integer.parseInt(input[0]);
int k = Integer.parseInt(input[1]);
int count = 0;
for (int i = 0; i < n; i++) {
if (Integer.parseInt(br.readLine()) % k == 0) {
count++;
}
}
System.out.println(count);
}
regards
shahensha
This could be slightly faster, based on limc's solution, BufferedReader should be faster still though.
import java.io.IOException;
import java.util.Scanner;
public class Main {
public static void main(String[] args) throws IOException {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int k = sc.nextInt();
int count = 0;
while (true) {
try {
if (sc.nextInt() % k == 0) {
count++;
}
} catch (NoSuchElementException e) {
break;
}
}
System.out.println(count);
}
}
How about this?
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int k = sc.nextInt();
int count = 0;
for (int i = 0; i < n; i++) {
if (sc.nextInt() % k == 0) {
count++;
}
}
System.out.println(count);
You may consider reading big chunks of input and then get the numbers from there.
Other change is, you may use Integer.parseInt() instead of Scanner.nextInt() although I don't know the details of each one, somethings tells me Scanner version performs a bit more computation to know if the input is correct. Another alternative is to convert the number yourself ( although Integer.parseInt should be fast enough )
Create a sample input, and measure your code, change a bit here and there and see what the difference is.
Measure, measure!
BufferedReader is supposed to be faster than Scanner. You will need to parse everything yourself though and depending on your implementation it could be worse.