Partition Equal Subset Sum in DSA Typescript - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to check if the total sum is even.

DSA Typescript

const totalSum = nums.reduce((acc, num) => acc + num, 0);
if (totalSum [1] 2 !== 0) {
  return false;
}

Drag options to blanks, or click blank then click option'

A/

B*

C%

D+

Attempts:

3 left

💡 Hint

Common Mistakes

Using division (/) instead of modulus (%) to check evenness.

Using multiplication (*) or addition (+) which do not check divisibility.

We use the modulus operator % to check if the total sum is divisible by 2 (even).

2fill in blank

medium

Complete the code to initialize the target sum for subset search.

DSA Typescript

const target = totalSum [1] 2;

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A/

B-

C+

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Multiplying instead of dividing.

Adding or subtracting which changes the target incorrectly.

We divide totalSum by 2 to find the target sum for one subset.

3fill in blank

hard

Fix the error in the loop that updates the dp array for subset sums.

DSA Typescript

for (let num of nums) {
  for (let j = target; j >= [1]; j--) {
    dp[j] = dp[j] || dp[j - num];
  }
}

Drag options to blanks, or click blank then click option'

Atarget

Bnum

C1

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Starting inner loop from 0 which causes incorrect dp updates.

Starting from target or 1 which does not prevent overwriting.

We start from target down to num to avoid using updated dp values in the same iteration.

4fill in blank

hard

Fill both blanks to create a dp array and initialize the base case.

DSA Typescript

const dp: boolean[] = new Array([1] + 1).fill(false);
dp[[2]] = true;

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Atarget

B0

C1

Dnums.length

Attempts:

3 left

💡 Hint

Common Mistakes

Initializing dp size with nums.length instead of target.

Setting dp[1] = true instead of dp[0].

We create dp array of size target+1 and set dp[0] = true as base case (sum 0 is always possible).

5fill in blank

hard

Fill all three blanks to complete the function that returns if partition is possible.

DSA Typescript

function canPartition(nums: number[]): boolean {
  const totalSum = nums.reduce((acc, num) => acc + num, 0);
  if (totalSum [1] 2 !== 0) return false;
  const target = totalSum [2] 2;
  const dp: boolean[] = new Array(target + 1).fill(false);
  dp[0] = true;
  for (const num of nums) {
    for (let j = target; j >= num; j--) {
      dp[j] = dp[j] || dp[j - num];
    }
  }
  return dp[[3]];
}

Drag options to blanks, or click blank then click option'

A%

B/

Ctarget

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong operators for checking evenness or division.

Returning dp[0] or dp[num] instead of dp[target].

We check if totalSum % 2 !== 0, divide totalSum by 2 for target, and return dp[target].