Search and display the comparison

[davidjayce]

I need help with the following question, I don't want the whole code but I really need help with this section. (DISPLAY THE NUMBER OF KEY COMPARISON FOR EACH SEARCH). Here is the question.

Method 1A
1A-1. Create one array arr1 of size 1000. Populate it with random numbers in the range from 0 to 2000.
1A-2. Randomly generate 5 numbers and try to search each number in the array.
1A-3. Display the number of key comparison for each search.
1A-4. Display a table like the following:


Target Number # of key comparison
356 (Not Found) 1000

54 256

1568 546

349 (not found) 1000

545 678

Average 696

[Jaybob66]

use an int for the count of key comparisons,

somewhere in your code there will be something like

if (itemA == itemB)
{
    // match found!
}

its the comparison that you need to count, regardless of whether the test was successful or not. So..

if (itemA == itemB)
{
    // found one!
}
comparisonCount++;

[Manga]

#include<iostream>
#include<ctime>

using namespace std;

int main () {

	srand(time(NULL));

	int arr1[1000];

	// fill with random numbers
	for (int i = 0; i < 1000; i++) {
		arr1[i] = rand() % 2001;
	}

	int arr2[5];

	// 5 more random numbers
	for (int i = 0; i < 5; i++) {
		arr2[i] = rand() % 2001;
	}

	int a = 0;
	
	//find matches and output the results
	for (int j = 0; j < 5; j++) {
		a = 0;
		for (int i = 0; i < 1000; i++) {
			if (arr2[j] == arr1[i]) {
				a++;
			}
		}
		cout << arr2[j] << " Number of matches: " << a << endl;
	}

	cin.get();
	return 0;
}

[Jaybob66]

Op didn't want the number of matches, they wanted the number of comparisons.

		for (int i = 0; i < 1000; i++) {
			if (arr2[j] == arr1[i]) {
                            // here's a match
			}
			a++;
		}

[Manga]

Do you mean the number of comparisons until a match was found?
Like this?

#include<iostream>
#include<ctime>

using namespace std;

int main () {

	srand(time(NULL));

	int arr1[1000];

	// fill with random numbers
	for (int i = 0; i < 1000; i++) {
		arr1[i] = rand() % 2001;
	}

	int arr2[5];

	// 5 more random numbers
	for (int i = 0; i < 5; i++) {
		arr2[i] = rand() % 2001;
	}

	int a = 0;
	
	//find matches and output the results
	for (int j = 0; j < 5; j++) {
		a = 0;
		for (int i = 0; i < 1000; i++) {
		    a++;
			if (arr2[j] == arr1[i]) {
				i = 1000;
			}
		}
		if (a < 1000) {
		cout << arr2[j] << " Number of comparisons until match found: " << a << endl;
		}
		else {
		    cout << arr2[j] << " No match found: " << a << endl;
		}
	}

	cin.get();
	return 0;
}