hey guys, right i have an array of 50 random integers and i have to check if any of them are the same, here is my code so far it only checks ajacent indexs
for (int i =0; i < 50; i++)
{
System.out.print("Student" + i + ": " );
customers[i] = (int)((Math.random()*10000)%10+1);
System.out.print(" " +customers[i]+ "\n");
if( duplicate == customers[i])
{
System.out.println("yup");
}
duplicate = customers[i];
}
Sort the array first. Then you can check just the next index. If it's ever the same, break.
Okay, I hate ridiculous limitations. If you want, you can do it like this without using a sort:
import java.util.ArrayList;
import java.lang.Math;
public class Main {
public static void main(String[] args) {
ArrayList<Integer> list = new ArrayList<Integer>();
Integer currentValue = 0;
int i = 0;
int limit = 20;
for(i = 0; i < limit; i++) {
list.add((int)(Math.random() * 100));
}
for(i = 0; i < limit; i++) {
currentValue = list.get(i);
list.set(i, -1);
if(list.contains(currentValue)) {
System.out.println("yup:" + currentValue);
return;
} else {
list.set(i, currentValue);
}
}
System.out.println("No duplicates!");
return;
}
}
Is it efficient? No.
Does it work? Yes.
I think, if you have to just use if/for functions, you have to make two loops:
for (int i =0; i < 50; i++)
{
customers[i] = (int)((Math.random()*10000)%10+1);
for ( int j = 0; j < i; j++)
{
if( customers[j] == customers[i])
{
// duplicated entry. do what you want
System.out.println("yup");
}
}
}
j < i? Customer[i+1] is not initialized yet, and it will compare every customer with itself.You could use Arrays.sort (see more at http://www.exampledepot.com/egs/java.util/coll_SortArray.html) to sort your data, and then check for duplicates.
You use value 0-10 so you can save your value in boolean array and it that way verify if this is duplicate or not:
boolean[] checker = new boolean[11];
for (int i =0; i < 50; i++) {
customers[i] = (int)((Math.random()*10000)%10+1);
if (checker[customers[i]]) {
System.out.println("yup"); //duplication
} else {
checker[customers[i]] = true;
}
}
You can use the below code if you are working with Integer array:
public class DuplicateInteger {
private static int countDuplicate;
public static int[] getDuplicateIntegers(int[] integerArray){
int duplicateIntegers[] = new int[integerArray.length];
countDuplicate = 0;
for(int i=0;i<integerArray.length;i++){
for(int j=i+1;j<integerArray.length;j++){
int replicaTest = 0;
if(integerArray[i]==integerArray[j]){
for(int k=0;k<countDuplicate;k++){
if(duplicateIntegers[k]==integerArray[i]){
replicaTest = 1;
}
}
if(replicaTest==0){
duplicateIntegers[countDuplicate] = integerArray[i];
countDuplicate++;
}
}
}
}
return duplicateIntegers;
}
public static void printDuplicateIntegers(int[] duplicateIntegers){
System.out.println("Duplicate Integers:");
System.out.println("-------------------");
for(int i=0;i<countDuplicate;i++){
System.out.println(duplicateIntegers[i]);
}
}
public static void main(String[] args){
int numberArray[] = {1, 2, 3, 4, 5, 6, 7, 1, 3, 5, 7};
printDuplicateIntegers(getDuplicateIntegers(numberArray));
}
}
