FastPrep
Problem · Hash Table

Number of Duplicates

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Problem statement

You are given a list of products, where each product has a name, price, and weight. Your task is to determine how many duplicate products are in the list. A duplicate product is defined as a product that has the same name, price, and weight as another product in the list.

Function Signature

public static int numDuplicates(List name, List price, List weight)

Parameters:

  1. List name: A list of strings where name[i] represents the name of the product at index i.
  2. List price: A list of integers where price[i] represents the price of the product at index i.
  3. List weight: A list of integers where weight[i] represents the weight of the product at index i.

Returns:

An integer denoting the number of duplicate products in the list.

Constraints

  • 1 ≤ n ≤ 10^5
  • 1 ≤ price[i], weight[i] ≤ 1000
  • name[i] consists of lowercase English letters (a-z) and has at most 10 characters.

Function

numDuplicates(name: List<String>, price: List<Integer>, weight: List<Integer>) → int

Examples

Example 1

name = ["ball", "box", "ball", "ball", "box"]price = [2, 2, 2, 2, 2]weight = [1, 2, 1, 1, 3]return = 2
"ball" at indices [0, 2, 3] have the same attributes (name = "ball", price = 2, weight = 1), so there are 2 duplicates. "box" at indices [1, 4] have different weights, so they are unique.

Example 2

name = ["ball", "box", "lamp", "brick", "pump"]price = [2, 2, 2, 2, 2]weight = [2, 2, 2, 2, 2]return = 0
Each product has unique attributes, so there are no duplicates.

More Amazon problems

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public static int numDuplicates(List<String> name, List<Integer> price, List<Integer> weight) {
  // write your code here
}
name["ball", "box", "ball", "ball", "box"]
price[2, 2, 2, 2, 2]
weight[1, 2, 1, 1, 3]
expected2
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