I try to make a lock on the incrementer "counter" in the Countrange method.
The counter should count under some conditions in the threads. If I complete the threads in order (not parallel) i get the right counter value over and over, but when i try to lock like i do in de program, it still isn't threadsafe, because i get diffrent counter values when i run the program a few times.
{
class Program
{
static int e, p, b, m;
static int counter = 0;
static int lok = 0;
static void Main(string[] args)
{
string input = Console.ReadLine();
string[] inputs = input.Split(' ');
counter = 0;
p = Convert.ToInt32(inputs[4]);
e = Convert.ToInt32(inputs[2]);
b = Convert.ToInt32(inputs[1]);
m = Convert.ToInt32(inputs[3]);
Thread[] ts = new Thread[p];
for (int t = 0; t < p; t++)
{
ts[t] = new Thread(countrange);
}
for (int t = 0; t < p; t++)
{
ts[t].Start(t);
}
for (int t = 0; t < p; t++)
{
ts[t].Join();
}
Console.Write(counter);
//Console.ReadKey();
}
public static void countrange(object mt)
{
int to = eind * (((int)mt + 1) / p) + verdeler + b;
int from = eind * (((int)mt) / p) + verdeler - a + b;
for (int i = from; i < to; i++)
{
proef = proef + moduler * keer;
}
{
if (proef % m == 0)
lock (mt)
{
counter++;
}
}
}
}
}
}
I made the lock static, now it works
Related
My code is not passing check50 and I can't find what's wrong.
// Sort pairs in decreasing order by strength of victory
void sort_pairs(void)
{
// TODO
for (int i = 0; i < pair_count - 1; i++)
{
int c = 0;
int high = preferences[pairs[i].winner][pairs[i].loser] -preferences[pairs[i].loser}[pairs[i].winner];
for (int j = i + 1; j < pair_count; j++)
{
if (preferences[pairs[j].winner][pairs[j].loser] - preferences[pairs[j].loser][pairs[j].winner] > high)
{
high = preferences[pairs[j].winner][pairs[j].loser] - preferences[pairs[j].loser][pairs[j].winner];
c = j;
}
}
pair temp = pairs[i];
pairs[i] = pairs[c];
pairs[c] = temp;
}
return;
}
I have two functions recursive and iterative to calculate money change; in the iterative version I needed to check for if the money is multiple of change (money modulus change is zero): is there a way to do iterative without checking for modulus?
public static int MoneyChangeRecur(int money, int[] changes)
{
int minChange = 0;
if (money == 0) return 0;
int min = int.MaxValue;
for (int i = 0; i < changes.Length; i++)
{
if (money >= changes[i])
{
minChange = MoneyChangeRecur(money - changes[i], changes);
if (minChange + 1 <= min)
{
min = minChange + 1;
}
}
}
return min;
}
static int IterativeMoneychange(int money)
{
int[] ar = new int[money + 1];
int[] change = { 6, 5, 1 };
int min = 9999;
int index = 0;
for (int i = 0; i < money+1; i++)
{
min = 99999;
index = 0;
bool modSet = false;
for (int j= 0; j <change.Length; j++)
{
if (i >= change[j])
{
int mod=(i % change[j]);
if(mod==0&&change[j]!=1)
{
if (!modSet) min = 99999;
if ((i-change[j] )< min)
{
min = (i - change[j]);
modSet = true;
}
}
else
{
if ((i - change[j]) < min)
{
min = (i - change[j]);
modSet = false;
}
}
}
}
if (min != 99999)// min = 0;
ar[i] = ar[min] +1;
}
return ar[money];
}enter code here
I have been doing some test in Groovy. I have done this code and I and get this error
Caught: groovy.lang.GroovyRuntimeException: This script or class could not be run.
It should either:
have a main method,
be a JUnit test or extend GroovyTestCase,
implement the Runnable interface,
or be compatible with a registered script runner. Known runners:
none
class Prime {
public static def prime(int x){
boolean result = true;
int i, j, temp;
temp = 0;
if (x < 2){
result = false;
}else {
for(i = 2; i < x && j == 0; i++){
temp = x % i;
if(temp == 0){
result = false;
}
}
}
return result;
}
static void main() {
long time_start, time_end, time_exe;
int primes = 0;
int N = (int) Math.pow(8, 5);
time_start = System.currentTimeMillis();
def fichero = new File("salida2.out")
for (int i = 0; i <= N; i ++) {
if (prime(i) == true) {
String line = "" + i + " is prime.";
fichero.append(line);
}
}
time_end = System.currentTimeMillis();
time_exe = time_end - time_start;
println("Execution time: " + time_exe + "milliseconds");
println("Prime Numbers Found: " + primes);
}
}
The signature of your main method is incorrect (Need String... args).
Change it to:
public static void main(String... args) {
class Program
{
static void Main(string[] args)
{
Console.Write("Enter Word : ");
string word = Console.ReadLine();
for (var i = 0; i < word.Length; i++)
{
var check = true;
var count = 0;
for (var k = i - 1; k <= 0; k--)
{
if (word[k] == word[i]) check = false;
}
if (check)
{
for (var j = i; j<= word.Length; j++)
{
if (word[i] == word[j]) count++;
}
Console.WriteLine(word[i] + " Occurs at " + count + " places.");
}
}
Console.ReadLine();
}
}
I have tried this one but not working.
The problem is that check is set to false if the string contains two adjacent identical characters. So if (check) {...} won't be executed, if this is the case. Another problem is that you set k to string position -1 in the first iteration of for (var k = i - 1; k <= 0; k--). If i=0, then k will be -1. You also need only one inner loop.
Here is a possible solution, although slightly different than your's.
class Program
{
static void Main(string[] args)
{
Console.Write("Enter Word : ");
string word = Console.ReadLine();
int i = 0;
while (i < word.Length)
{
int count = 1;
for (int k = i+1; k < word.Length; k++)
if (word[i] == word[k])
count++;
if (count>1)
{
Console.WriteLine(word[i] + " Occurs at " + count + " places.");
}
i += count; // continue next char or after after repeated chars
}
Console.ReadLine();
}
}
I've been trying to create a program where it takes an array input through an object and passes the parameter (simulation of ArrayList).
I keep getting the java.lang.ArrayIndexOutOfBoundsException in which I'm guessing I'm not accessing the array properly..
What can I do to enhance the test object and/ or the constructor?
public class MyArrayList{
public int[] x;
public MyArrayList( ){
x = new int[0];
}
public MyArrayList(int[] k)
{
for (int i = 0; i < x.length; i++)
x[i] = k[i];
k = x;
}
public void add(int index).......
public int size().....
public int get(int index).....
public void set(int index, int value).......
public String toString( )........
Below is the class I am having trouble with.
public class TestMyArrayList
{
public static void main(String[] args)
{
MyArrayList test = new MyArrayList();
test.x[0] = 1;
test.x[1] = 2;
test.x[2] = 3;
test.x[3] = 4;
test.x[4] = 5;
test.add(2);
test.set(1,3);
int a, b;
String c;
a = test.size( );
b = test.get(5);
c = test.toString( );
System.out.println("The size of the array is" + a);
System.out.println("The value at that position is " + b);
System.out.println("The resulting string is: " + c);
}
}
This line from your constructor is the only location (in the code you've shown) where the array x is initialized:
x = new int[0];
And it creates a zero length array. Assuming you are not reinitializing the array somewhere else then all these lines will definitely fail:
test.x[0] = 1;
test.x[1] = 2;
test.x[2] = 3;
test.x[3] = 4;
test.x[4] = 5;
Because your array length is zero. So:
Initialize your array to a more sensible value
Consider encapsulating the array so that callers cannot directly access it. This will make it much easier to code up your application in the long run
Side note (aka bonus):
This other constructor of yours:
public MyArrayList(int[] k) {
for (int i = 0; i < x.length; i++)
x[i] = k[i];
k = x;
}
has some issues as well:
You should reinitialize your array x to be the same size as the supplied array, prior to copying over the values.
The assignment k = x is basically a no-op, because it doesn't actually change what k was pointing to outside of the method.
Overall, it should look more like this:
public MyArrayList(int[] k) {
super();
if(k != null) {
x = new int[k.length];
for (int i = 0; i < x.length; i++) {
x[i] = k[i];
}
} else {
x = null;
}
}