i want to print a triangle/pyramid style like:
1
323
54345
7654567
here is my code:
int lines = 5;
for (int i = 1; i < lines; i++) {
for (int j = 1; j < lines-i; j++) {
System.out.print(" ");
}
for (int j = i; j > 1; j--) { //this for loop is my problem. any solution?
System.out.print(j);
}
for (int j = i; j < i+i; j++) {
System.out.print(j);
}
System.out.println();
}
what i got is
1
223
32345
4324567
i been studying codes while working at office and i think week long i still could not find a solution to this even i use search in Google.
i am only into enhancing my logic through conditionals and no heavy object oriented or recursion yet.
The problem in your first loop is a problem you figured out in your second one! (and it has something to do with the largest number in the loop)
for (int j = i; j > 1; j--) { //this for loop is my problem. any solution?
System.out.print(j);
}
Look at the numbers on the left of the pyramid. They start where the ones on the right end (every line of the pyramid is symmetrical). And the general formula for that number is i + i - 1, where i is the line number from your outer loop.
The second row starts at 2 * i - 1 = 2 * 2 - 1 = 3. The third row starts at 2 * 3 - 1 = 5 etc.
Your second inner loop should therefore look like this:
for (int j = i + i - 1; j > i; j--) {
System.out.print(j);
}
Here is the complete fixed source.
You have to start at the i-th odd number. This is i*2-1. And you stop at i. This also fixes a spacing difference introduced by changing it to lines = 4.
int lines = 4;
for (int i = 1; i <= lines; i++) {
for (int j = 1; j < lines-i+1; j++) {
System.out.print(" ");
}
for (int j = i*2-1; j > i; j--) { //this for loop is my problem. any solution?
System.out.print(j);
}
for (int j = i; j < i+i; j++) {
System.out.print(j);
}
System.out.println();
}
Run it here: http://ideone.com/AKsc1f
int lines = 4;
for (int i = 1; i <= lines; i++) {
for (int j = 1; j < lines-i+1; j++) {
System.out.print(" ");
}
//replace this
for(int j=0; j<i-1; j++) System.out.print(i*2-j-1);
System.out.print(i);
for(int j=; j<i-1;j++) System.out.print(i+j+1);
//==========
System.out.println();
}
Related
I'm a beginner at Java.
I was solving nested for loop questions... Then this question came up. After research and re-tries I couldn't get my head around it. It must be solved using only nested for loops.
This is what the question wants my code to output:
-----1-----
----333----
---55555---
--7777777--
-999999999-
This is as close as I got:
---------1
-------333
-----55555
---7777777
-999999999
This is my code:
for (int line = 1; line <= 9; line+=2) {
for (int j = 1; j <= (-1 * line + 10); j++) {
System.out.print("-");
}
for (int k = 1; k <= line; k++) {
System.out.print(line);
}
System.out.println();
}
You just need to add another for loop to print - on the right side.
Also now the first and the third loop will execute for half the number of times
for (int line = 1; line <= 9; line+=2) {
for (int j = 0; j <= (-1 * line + 10) / 2; j++) {
System.out.print("-");
}
for (int k = 1; k <= line; k++) {
System.out.print(line);
}
for (int j = 0; j <= (-1 * line + 10) / 2; j++) {
System.out.print("-");
}
System.out.println();
}
I need to print a table that looks like this if the user entered a 5 using nested for loops:
****5
***45
**345
*2345
12345
I've been working on this for hours and the closest I got was:
int size = scan.nextInt();
for (int i = 1; i <= size; i++)
{
for (int star = size-1; star >= i; star--)
System.out.print("*");
for (int k = 1; k <= i; k++)
System.out.print(i);
System.out.println();
}
Which outputs this:
****1
***12
**123
*1234
12345
You have too many loops; I find it easier to reason about zero based looping so I'm going to use that. Iterate i and j from 0 to size. If j + 1 is greater than size - i - 1 then we want to print j + 1. Otherwise, we want a star. Like,
for (int i = 0; i < size; i++) {
for (int j = 0; j < size; j++) {
if (j + 1 > size - i - 1) {
System.out.print(j + 1);
} else {
System.out.print('*');
}
}
System.out.println();
}
For size = 5 that outputs (as requested)
****5
***45
**345
*2345
12345
If you simply must have one based indices, that would be
for (int i = 1; i <= size; i++) {
for (int j = 1; j <= size; j++) {
if (j > size - i) {
System.out.print(j);
} else {
System.out.print('*');
}
}
System.out.println();
}
If you want to keep your loops and avoid if statements, you can tweak last loop by changing
for (int k = 1; k <= i; k++)
into
for (int k = 1+size-i; k <= size; k++)
Btw I also find it way easier to start loops from 0, so updated code would look like this:
int size = scan.nextInt();
for (int i = 0; i < size; i++)
{
for (int star = size-1; star > i; star--)
System.out.print("*");
for (int k = size-i; k <= size; k++)
System.out.print(k);
System.out.println();
}
I hope it helps
instead of getting a full triangle with 5 lines of "*" how do I replace every second line with a blank line, e.g. to look like this
5
555
55555
This is my code:
for(int i = 0; i < 5; i++) {
for(int j = i; j < 5; j++) {
System.out.print(" ");
}
for(int k = 0; k <= (i*2); k++) {
System.out.print("5");
}
System.out.println();
}
you need small modification in your code and you can get what you want.
for(int i = 0; i < 5; i++) {
for(int j = i; j < 5; j++) {
System.out.print(" ");
}
for(int k = 0; k <= (i*2); k++) {
if(i%2==0)
System.out.print("*");
}
System.out.println();
}
check it out.
Just test for i % 2
for(int i = 0; i < 5; i++) {
for(int j = i; j < 5; j++) {
System.out.print(" ");
}
for(int k = 0; k <= (i*2); k++) {
System.out.print(i % 2 == 0 ? "*" : " ");
}
System.out.println();
}
edit
If you want to print 5 instead or * then modify the code to use 5
Check this:
int num= 5; // 'num' denotes the number of lines
int numOfSpaces;
for(int i = 1; i <= num; i++) {
if( i%2 != 0) // checks whether the line number is odd. If odd, prints '*'
{
numOfSpaces = (num-i) / 2; // find the number of blank spaces
for(int j = 1; j <= numOfSpaces; j++) {
System.out.print(" ");
}
for(int k = 1; k <= i; k++) { // number of '*'s to be printed = current line number = i
System.out.print("*");
}
System.out.println();
}
else{
System.out.println(); // leaves every second line blank (ie.,if line number is even.)
}
}
//try this code. It may help you to achieve your output
[Check screen shot for the output of the below code][1]
for (int i = 0; i < 5; i++)
{
for (int j = 0; j < 5 - i; j++)
{
System.out.print(" ");
}
for (int k = 0; k <= i; k++)
{
if(i%2!=0)
{
System.out.print(" ");
}
else{
System.out.print("* ");
}
}
System.out.println();
}
The Code below is Working now.
A simple if condition will solve your problem. Just check if the
value of i is divisible by 2. If it is true then print a
blank line. Else Print * and you are done!
* will be printed on 1st, 3rd and 5th lines.
Blank Space will be printed on 2nd and 4th lines.
public class PrintPattern{
public static void main(String []args){
int lineNo=0; // New Variable for Line Number (Can Use variable 'i' also)
for(int i = 0; i < 5; i++) {
lineNo++;
for(int j = i; j < 5; j++) {
System.out.print(" ");
}
if(lineNo%2!=0){
for(int k = 0; k <= (i*2); k++)
System.out.print('*'); // Will print '*' (or '5') Sequence for Odd Lines - 1st, 3rd, 5th Lines
System.out.println();
}
else
System.out.println();// Will print Blank Line for Even Lines - 2nd and 4th Lines
}
}
}
Try this
for(int i = 0; i < 5; i++) {
for(int j = i; j < 5; j++) {
System.out.print(" ");
}
for(int k = 0; k <= (i*2); k++) {
System.out.print("5"); //Use 5 instaed of * to draw
}
System.out.println();
System.out.println(); //This one will solve your problem
}
Output will be:
5
555
55555
5555555
555555555
I think that you can just enter one more print statement inside the loop:
for(int i = 0; i < 5; i++) {
System.out.println();
for(int j = i; j < 5; j++) {
System.out.print(" ");
}
for(int k = 0; k <= (i*2); k++) {
System.out.print("*");
}
System.out.println();
}
Output
*
***
*****
*******
*********
I am trying to System.out.print() a diamond out of *'s. So far I have spent a good 5 hours on trying to figure out how to reverse print the bottom triangle of the diamond.
I can worry about the spacing to complete the diamond later. (I have it worked for the most part).
If someone could explain to me what I am doing wrong and how the right way works I would greatly appreciate it.
private static void diamond()
{
int numLines = 0;
System.out.println("How many lines would you like in the Diamond?");
numLines = scan.nextInt();
if (numLines / 2 == 0) //if number is even, make odd.
{
numLines++;
}
for(int i = 0; i <= numLines ; i++) // Controls #Lines
{
if(i <= numLines / 2)
{
for(int j = 0; j < i * 2 - 1; j++) // Controls #Stars small upright triangle
{
System.out.print("*");
}
}
else
{
for(int k = numLines; k > i / 2; k--) // Controls # of spaces
{
System.out.print("*");
}
/*for(int j = numLines/2 - i, l = i; l > j; j++) // Controls #Stars small upright triangle
{
String stars = "*";
System.out.print(stars);
}*/
}
System.out.println("");
}
}
`
What happens to your attempt is that you loop through the half (of the lines) of your diamond [the number of lines in second/first half] times.
You'd want to do a if-statement each loop, not an if and a for in each loop
Probably you want this
Just adjust it for user input values
public static void main(String[] args) {
System.out.print("Reverse diamond: \n");
for (int i = 1; i < 10; i += 2) {
for (int j = 0; j < 9 - i / 2; j++)
System.out.print(" ");
for (int j = 0; j < i; j++)
System.out.print("*");
System.out.print("\n");
}
System.out.print("\n\nDiamond from starts: \n");
for (int i = 7; i > 0; i -= 2) {
for (int j = 0; j < 9 - i / 2; j++)
System.out.print(" ");
for (int j = 0; j < i; j++)
System.out.print("*");
System.out.print("\n");
}
}
output:
I am trying to make my code print out the Asterisk in the image, you see below. The Asterisk are align to the right and they have blank spaces under them. I can't figure out, how to make it go to the right. Here is my code:
public class Assn4 {
public static void main(String[] args) {
for (int i = 0; i <= 3; i++) {
for (int j = 0; j <= i; j++) {
System.out.print("*");
}
for (int x = 0; x <= 1; x++) {
System.out.println(" ");
}
for (int j = 0; j <= i; j++) {
System.out.print("*");
}
}
System.out.println();
}
}
Matrix problems are really helpful to understand loops..
Understanding of your problem:
1) First, printing star at the end- That means your first loop should be in decreasing order
for(int i =7;i>=0; i+=i-2)
2) Printing star in increasing order- That means your second loop should be in increasing order
for(int j =0;j<=7; j++)
Complete code:
for(int i =7;i>=0; i=i-2){ // i=i-2 because *s are getting incremented by 2
for(int j =0;j<=7; j++){
if(j>=i){ // if j >= i then print * else space(" ")
System.out.print("*");
}
else{
System.out.print(" ");
}
}
System.out.println();// a new line just after printing *s
}
Starting loops with 1 can sometimes help you visualize better.
int stopAt = 7;
for (int i = 1; i <= stopAt ; i += 2) {
for (int j = 1; j <= stopAt; j++) {
System.out.print(j <= stopAt - i ? " " : "*");
}
System.out.println();
}
Notice, how each row prints an odd number of *s ending at the line with 7. So, you start with i at 1 and go through 3 1+2, 5 3+2, and then stopAt 7 5+2.
The nested for loop has to print 7 characters always to make sure *s appear right aligned. So, the loop runs from 1 to 7.
Here the complete code:
for(int i = 0; i < 8; i++){
if( i%2 != 0){
for(int x = 0; x < i; x++){
System.out.print("*");
}
}else{
System.out.println();
}
}