Majority Element Moore's Voting Algorithm in DSA C - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize the candidate variable.

DSA C

int findMajorityElement(int arr[], int n) {
    int count = 0;
    int candidate = [1];
    for (int i = 0; i < n; i++) {
        if (count == 0) {
            candidate = arr[i];
            count = 1;
        } else if (arr[i] == candidate) {
            count++;
        } else {
            count--;
        }
    }
    return candidate;
}

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A0

Barr[0]

C-1

Darr[1]

Attempts:

3 left

💡 Hint

Common Mistakes

Initializing candidate to 0 or -1 which may not be in the array.

Not initializing candidate before the loop.

The candidate is initially set to the first element of the array to start the voting process.

2fill in blank

medium

Complete the code to update the count when the current element matches the candidate.

DSA C

if (arr[i] == candidate) {
    [1];
}

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Acount = 0

Bcount = 1

Ccount++

Dcount--

Attempts:

3 left

💡 Hint

Common Mistakes

Decreasing count instead of increasing it.

Resetting count to 0 or 1 incorrectly.

When the current element matches the candidate, increase the count by one.

3fill in blank

hard

Fix the error in the condition to reset the candidate and count.

DSA C

if (count == [1]) {
    candidate = arr[i];
    count = 1;
}

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A0

B1

C-1

D2

Attempts:

3 left

💡 Hint

Common Mistakes

Resetting candidate when count is 1 instead of 0.

Using negative values in the condition.

The candidate and count reset when count reaches zero, not one.

4fill in blank

hard

Fill both blanks to complete the verification loop that confirms the majority element.

DSA C

int verifyCount = 0;
for (int i = 0; i < n; i++) {
    if (arr[i] [1] candidate) {
        verifyCount [2];
    }
}
if (verifyCount > n / 2) {
    return candidate;
} else {
    return -1;
}

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A==

B!=

C++

D--

Attempts:

3 left

💡 Hint

Common Mistakes

Using '!=' instead of '==' in the condition.

Decrementing verifyCount instead of incrementing.

We check if each element equals the candidate and increment verifyCount if true.

5fill in blank

hard

Fill all three blanks to complete the main function that tests the majority element function.

DSA C

#include <stdio.h>

int findMajorityElement(int arr[], int n);

int main() {
    int arr[] = {2, 2, 1, 1, 1, 2, 2};
    int n = [1];
    int result = findMajorityElement(arr, [2]);
    if (result != [3]) {
        printf("Majority element is %d\n", result);
    } else {
        printf("No majority element found\n");
    }
    return 0;
}

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A7

Barr

C-1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Passing wrong array length.

Using 0 instead of -1 for no majority element.

The array length is 7, passed twice, and -1 indicates no majority element.