[SOLVED] Help with Matrix

[Bernard Robitaille]

Ok, i recieved a basic program to build which required me to build a matrix of a size chosen by the user and with his inputs of the numbers.I have to then find the third smallest value. For some reason i can't seem to get that third number. This is my program, one of my problems is that it doesnt really work right and 2 it carries the initialisation problem. ( Its a french class so ignore the french words;) )

import java.util.Scanner;

public class Laboratoire3s
{

public static void main(String[] args)
{
int i,x,y;
double t1,t2,t3;
Scanner scan = new Scanner(System.in);

System.out.println("Entrez le nombre de case dans votre tableau");
double[] notes = new double[scan.nextInt()];
t1=notes[0];
t2=notes[0];
t3=notes[0];
System.out.println("Maintenant, entrez les entier destine a remplire votre tableau");
for (i=0;i<notes.length;i++)
notes[i]=scan.nextInt();
y=0;
x=0;



for (i=0;i<notes.length;i++)
{
if (t1>notes[i]);
{
t1=notes[i];
x = i;
}

if (notes[i]<t2 && x != i)
{
t2=notes[i];
y = i;
}
if(notes[i]<t2 && y != i)
t3=notes[i];
}

System.out.println(t1 +" et "+ t2 +" et " + t3);

}

}

[Eranga]

You have just added an empty statement here in if condition.

if (t1>notes[i]);

What's the point?

[Bernard Robitaille]

its to say if the value of that piece of the matrix is smaller than the one in it already if so it will put it.

[Eranga]

I'm not clear what you say. Can say what's doing on this code segment.

if (t1>notes[i]);
{
t1=notes[i];
x = i;
}

[Bernard Robitaille]

This piece of code checks if the value of the case at the [i] location in the matrix is lower than the one already in t1, if it is it will deposit it into t1 as shown on t1=notes[i] the x is to memorise at which case this number was taken to prevent the two other following numbers, t2 and t3 from taking that same case as the lowest. I am very sorry about the inapropriate lingo, since i am doing this class in french the translating is rather difficult. My main problem is the initialisation of my variables, seeing as they are initialised at either case [0] or at 0 this prevents me from checking for the second a third numbers accuratly. i would really like to find a sugestion on how to sort my matrix in order to find the third lowest value. Any sugestion would be greatly appreciated.

[Eranga]

Are you sure that if the condition true, things you have explain is happen. Even the condition is true or false the following two lines are executing.

t1=notes[i];
x = i;

Reason is, that if condition has an empty statement. You have added a colon at the end.

if (t1>notes[i])[B];[/B]

[CJSLMAN]

if (t1>notes[i]);

Two things wrong with this:

• t1 has not been initialized and ...
• Like Eranga has said, the if shouldn't end with a ","

Luck,
CJSL

[Eranga]

Our thread starter do something mess to me.

t1=notes[0];

Did you notice that Chris?

[CJSLMAN]

This piece of code checks if the value of the case at the [i] location in the matrix is lower than the one already in t1

The above isn't going to happen because t1 hasn't been assigned a value (as explained in my previous post).

t1=notes[0];
t2=notes[0];
t3=notes[0];

The matrix doesn't have any values when the above assignments happen, so t1, t2 & t3 are initially equal to null.

Won't something like a bubble sort work in this case? Something like:

• Fill the array with ints (not sure why it's being called a matrix when it's a 1d array)
• sort the array elements
• Print notes[3]

Does that sound right?

Luck,
CJSL

[Bernard Robitaille]

Thank you very much, i hadnt learned the name of an Array, with it i simply used the sort array command and took the third value in the array. AGain thanks to your help i was able to fix the bugs in my program. Good day sir.

[Eranga]

Fine. If you have solve the problem please mark the thread solved.