Problem: Count Pairs Whose Sum is Less than Target

Easy

15 min

Explore methods to count distinct index pairs in an integer array whose sums are strictly less than a given target. Learn to apply the two-pointer technique to solve this problem efficiently, understand the constraints, and practice implementing your solution in a hands-on coding environment.

Statement

You are given a 0-indexed integer array, nums, of length $n$ , and an integer target. Your task is to determine the number of distinct pairs of indexes $(i, j)$ such that:

$0 \leq i < j < n$ (i.e., $i$ comes before $j$ in the array)
The sum of the elements of the indexes $(i, j)$ , (i.e., $\text{nums}[i] + \text{nums}[j]$ ), is strictly less than the target.

Constraints:

$n =$ nums.length
$1 \leq n\leq 50$
$-50 \leq$ nums[i], target $\leq 50$

Problem: Count Pairs Whose Sum is Less than Target

Easy

15 min

Statement

You are given a 0-indexed integer array, nums, of length $n$ , and an integer target. Your task is to determine the number of distinct pairs of indexes $(i, j)$ such that:

$0 \leq i < j < n$ (i.e., $i$ comes before $j$ in the array)
The sum of the elements of the indexes $(i, j)$ , (i.e., $\text{nums}[i] + \text{nums}[j]$ ), is strictly less than the target.

Constraints:

$n =$ nums.length
$1 \leq n\leq 50$
$-50 \leq$ nums[i], target $\leq 50$

Problem: Count Pairs Whose Sum is Less than Target

Statement

Examples

Understand the problem

Figure it out!

Try it yourself

Problem: Count Pairs Whose Sum is Less than Target

Statement

Examples

Understand the problem

Figure it out!

Try it yourself