Hany Moh. - 1 year ago 60
Java Question

# find repeated elements and count of their

i want to give an array of integers, determine the number of repeated integers and their counts.

this is the full code after edit

``````// Enter array size:
Scanner input = new Scanner(System.in);
System.out.println("Enter array size: ");
int size = input.nextInt();
int[] crr_array = new int[size];
int[] new_array= new int[size];
int[] times = new int[size];

// Enter array elements:
System.out.println("Enter array elements: ");
for (int i = 0; i < crr_array.length; i++) {
crr_array[i] = input.nextInt();
times[i] = 1;
}

//search

for (int j = 0; j < crr_array.length; j++) {

for (int i = j; i < crr_array.length; i++) {

if (crr_array[j] == crr_array[i] && j != i) {

new_array[i] = crr_array[i];
times[i]++;
}

}

}

//Printing output
for (int i = 0; i <  new_array.length; i++) {
System.out.println("\t" + crr_array[i] + "\t" +  new_array[i] + "\t" + times[i]);

}
``````

I want to get output like that

``````  count of elements  //3
element: count times //2 times
element: count times //3times
element: count times //2 times
``````

i hope to get output like

``````There are 3 repeated numbers:
22: 2 times
4: 3 times
1: 2 times
``````

This kind of problems can be easy solved by dictionaries (HashMap in Java).

``````  // The solution itself
HashMap<Integer, Integer> repetitions = new HashMap<Integer, Integer>();

for (int i = 0; i < crr_array.length; ++i) {
int item = crr_array[i];

if (repetitions.containsKey(item))
repetitions.put(item, repetitions.get(item) + 1);
else
repetitions.put(item, 1);
}

// Now let's print the repetitions out
StringBuilder sb = new StringBuilder();

int overAllCount = 0;

for (Map.Entry<Integer, Integer> e : repetitions.entrySet()) {
if (e.getValue() > 1) {
overAllCount += 1;

sb.append("\n");
sb.append(e.getKey());
sb.append(": ");
sb.append(e.getValue());
sb.append(" times");
}
}

if (overAllCount > 0) {
sb.insert(0, " repeated numbers:");
sb.insert(0, overAllCount);
sb.insert(0, "There are ");
}

System.out.print(sb.toString());
``````
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