I want output like:
Dividend 1 : ...
Dividend 2 : ...
Dividend 3 : ...
Here is my code:
int i = 0;
while(i < dividendRates.length) {
System.out.println(String.format("Dividend %d : ", i) + (income * dividendRates[i]) );
i = i + 1;
}
But dividend number start with 0.
The easy way is just create new variable like 'int e = 1;' and use it, but I want to use variable 'i' and have output start with 1.
What should I do?
You can try the following code and I hope get the point:
int i = 1;
while( (i-1) < dividendRates.length) {
System.out.println(String.format("Dividend %d : ", i) + (income*dividendRates[i]) );
i = i + 1;
}
Related
I managed to solve this, below is my solution :
public class ProblemA001k {
public static void main(String[] args) {
System.out.println("Sum from 1" + " to " + divQ + ":" + sum2);
System.out.println();
divQ += q;
newQ += q;
sum1 = 0;
sum2 = 0;
}
key.close();
}
}
Now I was told to modify my solution so that it uses ONLY ONE LOOP.
I have 3 loops in the code above, even when I tried using only 2 loops I struggled. but ONE LOOP ? I don't know how to improve my code. Please help me.
This is a Mathematic problem.
If you know that you can find the sum of all integers from 1 to X, you just need to do X * (X+1) / 2.
You can find all the batch values easily.
Sum from 1 to 400: 80200
Sum from 401 to 450: 21275
Sum from 1 to 450: 101475
Will be found like this :
450 * 451 / 2 = 101475 (1 to 450)
400 * 401 / 2 = 80200 (1 to 400)
101475 - 80200 = 21275 (401 to 450)
With this, you can limit the loop to just calculate the values from q to n by incrementing by q
And a quick code to do it :
static void sum(int n, int q){
int i = q;
int sum, tmp=0;
while(i < n){
sum = i * (i+1) / 2;
System.out.println(String.format("Sum from %d to %d : %d", i-q+1 , i, sum - tmp));
System.out.println(String.format("Sum from %d to %d : %d", 1, i, sum));
tmp = sum;
i += q;
}
}
And I run it with
public static void main(String[] args){
sum(500, 50);
}
to have this result
Sum from 1 to 50 : 1275
Sum from 1 to 50 : 1275
Sum from 51 to 100 : 3775
Sum from 1 to 100 : 5050
Sum from 101 to 150 : 6275
Sum from 1 to 150 : 11325
Sum from 151 to 200 : 8775
Sum from 1 to 200 : 20100
Sum from 201 to 250 : 11275
Sum from 1 to 250 : 31375
Sum from 251 to 300 : 13775
Sum from 1 to 300 : 45150
Sum from 301 to 350 : 16275
Sum from 1 to 350 : 61425
Sum from 351 to 400 : 18775
Sum from 1 to 400 : 80200
Sum from 401 to 450 : 21275
Sum from 1 to 450 : 101475
The good think with this solution is the number of loop, this will increment by q instead of 1
Note : The solution is a quick implementation, this could be done better.
EDIT :
Thanks to Margaret Bloom in the comments to point out the name of this formula :) For more information, you are welcome to look at Triangular Number
This should do it:
int totalSum = 0;
int batchSum = 0;
for (int i = 1; i <= n; i++) {
totalSum += i;
batchSum += i;
if (i % q == 0) {
System.out.println("Sum from " + (i - q + 1) + " to " + i + ":" + batchSum);
System.out.println("Sum from 1 to " + i + ":" + totalSum);
batchSum = 0;
}
}
Edit:
The better Math way:
int lastTotalSum = 0;
for (int i = 1; i <= n / q; i++ ) {
int top = i * q;
int totalSum = top * (top + 1) / 2;
int batchSum = totalSum - lastTotalSum;
System.out.println("Sum from " + (top - q + 1) + " to " + top + ":" + batchSum);
System.out.println("Sum from 1 to " + top + ":" + totalSum);
lastTotalSum = totalSum;
}
I found a nice solution with java8 Streams:
int n=1000;
int q=50;
int length = n/q -1;
int[] previousSum={0};
IntStream.range(0, length).map(i -> (i+1)*q).forEach(s -> {
int sum=(s*(s+1))/2;
int batch = sum - previousSum[0];
previousSum[0] = sum;
System.out.println("Sum from " + (s - q + 1) + " to " + s + ":" + batch);
System.out.println("Sum from 1 to " + s + ":" + sum);
});
Do one loop iterating entire range and use indexes to decide whether to add, reset or print your sums.
Hope this gives your right idea, if you still dont know I can illustrate it a bit more.
I have the following issue: when trying to add to a sum of BigIntegers the outcome remains 0.
Here is the code:
public void NumberOfOutcomes(int x, int y){
BigInteger first = BigInteger.valueOf(0);
BigInteger second = BigInteger.valueOf(0);
for(int i = 0; i <= (x / 2); i++){
first.add( fac(x - i).divide((fac(x - 2*i).multiply(fac(i)))) );
System.out.println("First " + first.add( fac(x - i).divide((fac(x - 2*i).multiply(fac(i)))) ));
}
for(int i = 0; i <= (y / 2); i++){
second.add( fac(y - i).divide((fac(y - 2*i).multiply(fac(i)))) );
System.out.println("Second " + second.add( fac(y - i).divide((fac(y - 2*i).multiply(fac(i)))) ));
}
System.out.println("First " + first);
System.out.println("Second " + second);
System.out.println(first.multiply(second));
}
Here fac is the factorial function.
Here is what comes on the terminal:
points1.NumberOfOutcomes(2, 3)
First 1
First 1
Second 1
Second 2
First 0
Second 0
0
This is because BigInteger is immutable which means that its value does not change. So first.add(x) will create a new BigInteger containing the computations result, i.e. just reassign the result to first, like first = first.add(...).
The add method of BigInteger class returns the sum of the operand and the value already stored in the the object itself. But it does not store the result in the object (first or second).
It doesn't work in the same way as
first += value;
actually, you have to make it look like this:
first = first.add(value);
I'm a bit of a newbie at Java and I have to multiply 52 numbers with each other ranging anywhere from 0 to 2000. I already tried using *= without BigDecimal but the result gives me 0.0.
Here is my code:
BigDecimal productOfStock1 = BigDecimal.ZERO;
for(int k = 1; k <= N; k++){
for(int i = 1; i <= n; i++){
if (i == 1){
stockPrice[k][i] = stockZero*Math.pow(e, form + sigma*(randomno.nextGaussian()));
}
else {
stockPrice[k][i] = stockPrice[k][i-1]*Math.pow(e, form + sigma*(randomno.nextGaussian()));
}
//sumOfStock += stockPrice[k][i];
//productOfStock *= stockPrice[k][i];
productOfStock1 = productOfStock1.multiply(BigDecimal.valueOf(stockPrice[k][i]));
System.out.println(/*"Stock at [" + i + "] for N = " + N + " and path number " + k + " is " + */stockPrice[k][i]);
}
}
System.out.println(productOfStock1);
This gives me 0E-637 instead of the big number it is supposed to give me. Any help is appreciated.
BigDecimal productOfStock1 = BigDecimal.ZERO;
you need to initialize it with 1, because
0 * X = 0
(except for X= 1/0 :) )
Don't initialize productOfStock1 to 0, use 1 instead. Otherwise, you'll always be multiplying by 0.
I wrote a programm to get the cross sum of a number:
So when i type in 3457 for example it should output 3 + 4 + 5 + 7. But somehow my logik wont work. When i type in 68768 for example i get 6 + 0 + 7. But when i type in 97999 i get the correct output 9 + 7 + 9. I know that i have could do this task easily with diffrent methods but i tried to use loops . Here is my code: And thanks to all
import Prog1Tools.IOTools;
public class Aufgabe {
public static void main(String[] args){
System.out.print("Please type in a number: ");
int zahl = IOTools.readInteger();
int ten_thousand = 0;
int thousand = 0;
int hundret = 0;
for(int i = 0; i < 10; i++){
if((zahl / 10000) == i){
ten_thousand = i;
zahl = zahl - (ten_thousand * 10000);
}
for(int f = 0; f < 10; f++){
if((zahl / 1000) == f){
thousand = f;
zahl = zahl - (thousand * 1000);
}
for(int z = 0; z < 10; z++){
if((zahl / 100) == z){
hundret = z;
}
}
}
}
System.out.println( ten_thousand + " + " + thousand + " + " + hundret);
}
}
Is this what you want?
String s = Integer.toString(zahl);
for (int i = 0; i < s.length() - 1; i++) {
System.out.println(s.charAt(i) + " + ");
}
System.out.println(s.charAt(s.length()-1);
The problem with the code you've presented is that you have the inner loops nested. Instead, you should finish iterating over each loop before starting with the next one.
What's happening at the moment with 68768 is when the outer for loop gets to i=6, the ten_thousand term gets set to 6 and the inner loops proceed to the calculation of the 'thousand' and 'hundred' terms - and does set those as you expect (and leaving zahl equal to 768 - notice that you don't decrease zahl at the hundreds stage)
But then the outer loop continues looping, this time with i=7. With zahl=768, zahl/1000 = 0' so the 'thousand' term gets set to 0. The hundred term always gets reset to 7 with zahl=768.
The 97999 works because the thousand term is set on the final iteration of the 'i' loop, so never gets reset.
The remedy is to not nest the inner loops - and it'll perform a lot better too!
You should do something like this
input = 56789;
int sum = 0;
int remainder = input % 10 // = 9;
sum += remainder // now sum is sum + remainder
input /= 10; // this makes the input 5678
...
// repeat the process
To loop it, use a while loop instead of a for loop. This a great example of when to use a while loop. If this is for a class, it will show your understanding of when to use while loops: when the number of iterations is unknown, but is based on a condition.
int sum = 0;
while (input/10 != 0) {
int remainder = input % 10;
sum += remainder;
input /= 10;
}
// this is all you really need
Your sample is a little bit complicated. To extract the tenthousand, thousand and the hundreds you can simply do this:
private void testFunction(int zahl) {
int tenThousand = (zahl / 10000) % 10;
int thousand = (zahl / 1000) % 10;
int hundred = (zahl / 100) % 10;
System.out.println(tenThousand + "+" + thousand + "+" + hundred);
}
Bit as many devs reported you should convert it to string and process character by character.
I couldn't figure out how the decrement operator (e--)
works in code below, so i wrote the other class below it
to get the same result. I want to know how the decrement operator
achieves that result in the Power class. - Newbie.
int result, e;
for(int i=0; i < 10; i++) {
result = 1;
e = i;
while(e > 0) {
result *= 2;
e--;
}
System.out.println("2 to the " + i +
" power is " + result);
}
Code written to achieve same result
int result = 1;
for(int i=0; i < 10; i++) {
if (i > 0) {
result*=2;
}
System.out.println("2 to the " + i +
" power is " + result);
}
So the first example is resetting result for each iteration of the main for loop, so it needs to recalculate from scratch each time, where as the second example is keeping the previous computed value. The if in the second example is not needed is it.
The decrement operator modifies the variable on which it's called. So e-- is effectively e = e - 1 (except the overall result of the expression is different, see below).
This code:
result = 1;
e = i;
while(e > 0) {
result *= 2;
e--;
}
starts with result = 1 and then loops for i iterations doubling the value in result. Equivalent code using for which you seem more comfortable with:
result = 1;
for (e = 0; e < i; e++) {
result *= 2;
}
There are two forms of the decrement (and increment) operator: Prefix and postfix, depending on whether the operator is before (prefix) or after (postfix) its operand. Either could be used in the code you were asking about, because the only difference is the result of the expression.
Prefix: Suppose we have x = 5. The expression --x has the value 4: First we decrement x, then we take its new value as the result of the expression.
Postfix: Suppose we had x = 5 (again). The expression x-- has the value 5, with x ending up containing 4: First we grab the current value of x as the result of the expression, then we decrement it (because the -- is after x).
int x, r;
x = 5;
r = --x; // Prefix
System.out.println("r = " + r + ", x = " + x); // "r = 4, x = 4"
x = 5;
r = x--; // Postfix
System.out.println("r = " + r + ", x = " + x); // "r = 5, x = 4"
i figure out that by placing a System.out.println(e) i could "see" the variable "e" behavior in order to make sense of the decrement.
class Power {
public static void main(String args[]) {
int e;
int result;
for(int i=0; i < 10; i++) {
result =1 ;
e = i;
while(e > 0) {
System.out.println(e); // not part of the original program
result *= 2 ;
e--;
System.out.println(e); // not part of the original program
}
//System.out.println("2 to the " + i +
//" power is " + result);
}
This is the output:
C:\Users\enrique\Desktop\Hello.java>java Power: 1, 0, 2, 1, 1, 0, 3
e = 1(iteration 1), 2^1, e (1) decremented to 0, e = 2 (iteration 2), 2^2, e(2) decremented to 1, e = 1 re-enter The while but is ignored as 2^1 is already registered, e (1) decremented to 0, e = 3 (iteration 3), 2^3…