|
| 1 | +--- |
| 2 | +id: tuple-with-same-product |
| 3 | +title: Tuple with Same Product |
| 4 | +sidebar_label: 1726 - Tuple with Same Product |
| 5 | +tags: |
| 6 | +- Array |
| 7 | +- Hash Table |
| 8 | +- Counting |
| 9 | + |
| 10 | +description: "This is a solution to theTuple with Same Product problem on LeetCode." |
| 11 | +--- |
| 12 | + |
| 13 | +## Problem Description |
| 14 | +Given an array nums of distinct positive integers, return the number of tuples (a, b, c, d) such that a * b = c * d where a, b, c, and d are elements of nums, and a != b != c != d. |
| 15 | + |
| 16 | +### Examples |
| 17 | + |
| 18 | +**Example 1:** |
| 19 | +``` |
| 20 | +Input: nums = [2,3,4,6] |
| 21 | +Output: 8 |
| 22 | +Explanation: There are 8 valid tuples: |
| 23 | +(2,6,3,4) , (2,6,4,3) , (6,2,3,4) , (6,2,4,3) |
| 24 | +(3,4,2,6) , (4,3,2,6) , (3,4,6,2) , (4,3,6,2) |
| 25 | +
|
| 26 | +``` |
| 27 | + |
| 28 | +**Example 2:** |
| 29 | + |
| 30 | +``` |
| 31 | +Input: nums = [1,2,4,5,10] |
| 32 | +Output: 16 |
| 33 | +Explanation: There are 16 valid tuples: |
| 34 | +(1,10,2,5) , (1,10,5,2) , (10,1,2,5) , (10,1,5,2) |
| 35 | +(2,5,1,10) , (2,5,10,1) , (5,2,1,10) , (5,2,10,1) |
| 36 | +(2,10,4,5) , (2,10,5,4) , (10,2,4,5) , (10,2,5,4) |
| 37 | +(4,5,2,10) , (4,5,10,2) , (5,4,2,10) , (5,4,10,2) |
| 38 | +``` |
| 39 | + |
| 40 | + |
| 41 | +### Constraints |
| 42 | +- `1 <= nums.length <= 1000` |
| 43 | +- `1 <= nums[i] <= 10^4` |
| 44 | +- `All elements in nums are distinct.` |
| 45 | + |
| 46 | +## Solution for Path With Minimum Effort Problem |
| 47 | +### Approach |
| 48 | +#### Brute Force - |
| 49 | +- The first approach that is find all sets of a , b ,c , d by using 4 nested loop . Time Complexity of this approach is very high $ O(N^4)$ which is not feasible |
| 50 | +#### Optimized Approach Using Hashmap |
| 51 | + |
| 52 | +##### Calculate Product Pairs: |
| 53 | + |
| 54 | +- Iterate through each possible pair of elements in the array. |
| 55 | +- For each pair (nums[i], nums[j]), calculate their product. |
| 56 | +- Store the product in a hash map (mp) where the key is the product and the value is the count of pairs that produce this product. |
| 57 | +##### Count Tuples: |
| 58 | +- Iterate through the hash map. |
| 59 | +- For each unique product that appears n times, the number of ways to choose 2 pairs from n pairs is given by the combination formula C(n, 2) = n * (n - 1) / 2. |
| 60 | +- Since each valid tuple of pairs can be permuted in 8 different ways (each pair can be swapped with the other), multiply the result by 8. |
| 61 | +##### Return the Result: |
| 62 | +- Sum up the counts from all unique products to get the total number of valid tuples and multiply by 8. |
| 63 | + |
| 64 | +<Tabs> |
| 65 | + <TabItem value="Solution" label="Solution"> |
| 66 | + |
| 67 | + #### Implementation |
| 68 | + ```jsx live |
| 69 | + function Solution(arr) { |
| 70 | + var tupleSameProduct = function(nums) { |
| 71 | + let mp = new Map(); |
| 72 | + |
| 73 | + for (let i = 0; i < nums.length; ++i) { |
| 74 | + for (let j = i + 1; j < nums.length; ++j) { |
| 75 | + let product = nums[i] * nums[j]; |
| 76 | + mp.set(product, (mp.get(product) || 0) + 1); |
| 77 | + } |
| 78 | + } |
| 79 | + |
| 80 | + let ans = 0; |
| 81 | + |
| 82 | + for (let count of mp.values()) { |
| 83 | + ans += (count * (count - 1)) / 2; |
| 84 | + } |
| 85 | + |
| 86 | + return ans * 8; |
| 87 | + }; |
| 88 | + const input = [2,3,4,6] |
| 89 | + const output = tupleSameProduct(input) |
| 90 | + return ( |
| 91 | + <div> |
| 92 | + <p> |
| 93 | + <b>Input: </b> |
| 94 | + {JSON.stringify(input)} |
| 95 | + </p> |
| 96 | + <p> |
| 97 | + <b>Output:</b> {output.toString()} |
| 98 | + </p> |
| 99 | + </div> |
| 100 | + ); |
| 101 | + } |
| 102 | + ``` |
| 103 | + |
| 104 | + #### Complexity Analysis |
| 105 | + |
| 106 | + - Time Complexity: $ O(N^2) $ |
| 107 | + - Space Complexity: $ O(N^2)$ |
| 108 | + |
| 109 | + ## Code in Different Languages |
| 110 | + <Tabs> |
| 111 | + <TabItem value="JavaScript" label="JavaScript"> |
| 112 | + <SolutionAuthor name="@hiteshgahanolia"/> |
| 113 | + ```javascript |
| 114 | + var tupleSameProduct = function(nums) { |
| 115 | + let mp = new Map(); |
| 116 | + |
| 117 | + for (let i = 0; i < nums.length; ++i) { |
| 118 | + for (let j = i + 1; j < nums.length; ++j) { |
| 119 | + let product = nums[i] * nums[j]; |
| 120 | + mp.set(product, (mp.get(product) || 0) + 1); |
| 121 | + } |
| 122 | + } |
| 123 | + |
| 124 | + let ans = 0; |
| 125 | + |
| 126 | + for (let count of mp.values()) { |
| 127 | + ans += (count * (count - 1)) / 2; |
| 128 | + } |
| 129 | + |
| 130 | + return ans * 8; |
| 131 | +}; |
| 132 | + ``` |
| 133 | + |
| 134 | + </TabItem> |
| 135 | + <TabItem value="TypeScript" label="TypeScript"> |
| 136 | + <SolutionAuthor name="@hiteshgahanolia"/> |
| 137 | + ```typescript |
| 138 | + function tupleSameProduct(nums: number[]): number { |
| 139 | + let mp = new Map<number, number>(); |
| 140 | + |
| 141 | + for (let i = 0; i < nums.length; ++i) { |
| 142 | + for (let j = i + 1; j < nums.length; ++j) { |
| 143 | + let product = nums[i] * nums[j]; |
| 144 | + mp.set(product, (mp.get(product) || 0) + 1); |
| 145 | + } |
| 146 | + } |
| 147 | +
|
| 148 | + let ans = 0; |
| 149 | + |
| 150 | + for (let count of mp.values()) { |
| 151 | + ans += (count * (count - 1)) / 2; |
| 152 | + } |
| 153 | + |
| 154 | + return ans * 8; |
| 155 | +} |
| 156 | +
|
| 157 | + ``` |
| 158 | + </TabItem> |
| 159 | + <TabItem value="Python" label="Python"> |
| 160 | + <SolutionAuthor name="@hiteshgahanolia"/> |
| 161 | + ```python |
| 162 | + from collections import defaultdict |
| 163 | +
|
| 164 | +class Solution: |
| 165 | + def tupleSameProduct(self, nums: list[int]) -> int: |
| 166 | + mp = defaultdict(int) |
| 167 | + |
| 168 | + for i in range(len(nums)): |
| 169 | + for j in range(i + 1, len(nums)): |
| 170 | + product = nums[i] * nums[j] |
| 171 | + mp[product] += 1 |
| 172 | +
|
| 173 | + ans = 0 |
| 174 | + |
| 175 | + for count in mp.values(): |
| 176 | + ans += (count * (count - 1)) // 2 |
| 177 | + |
| 178 | + return ans * 8 |
| 179 | +
|
| 180 | + ``` |
| 181 | + |
| 182 | + </TabItem> |
| 183 | + <TabItem value="Java" label="Java"> |
| 184 | + <SolutionAuthor name="@hiteshgahanolia"/> |
| 185 | + ```java |
| 186 | + import java.util.HashMap; |
| 187 | +import java.util.Map; |
| 188 | +
|
| 189 | +public class Solution { |
| 190 | + public int tupleSameProduct(int[] nums) { |
| 191 | + Map<Integer, Integer> mp = new HashMap<>(); |
| 192 | + |
| 193 | + for (int i = 0; i < nums.length; ++i) { |
| 194 | + for (int j = i + 1; j < nums.length; ++j) { |
| 195 | + int product = nums[i] * nums[j]; |
| 196 | + mp.put(product, mp.getOrDefault(product, 0) + 1); |
| 197 | + } |
| 198 | + } |
| 199 | +
|
| 200 | + int ans = 0; |
| 201 | + |
| 202 | + for (Map.Entry<Integer, Integer> entry : mp.entrySet()) { |
| 203 | + int n = entry.getValue(); |
| 204 | + ans += (n * (n - 1)) / 2; |
| 205 | + } |
| 206 | + |
| 207 | + return ans * 8; |
| 208 | + } |
| 209 | +} |
| 210 | +
|
| 211 | + ``` |
| 212 | + |
| 213 | + </TabItem> |
| 214 | + <TabItem value="C++" label="C++"> |
| 215 | + <SolutionAuthor name="@hiteshgahanolia"/> |
| 216 | + ```cpp |
| 217 | + class Solution { |
| 218 | +public: |
| 219 | + int tupleSameProduct(vector<int>& nums) { |
| 220 | + unordered_map<int, int> mp; |
| 221 | + |
| 222 | + for (int i = 0; i < nums.size(); ++i) { |
| 223 | + for (int j = i + 1; j < nums.size(); ++j) { |
| 224 | + int product = nums[i] * nums[j]; |
| 225 | + mp[product]++; |
| 226 | + } |
| 227 | + } |
| 228 | +
|
| 229 | + int ans = 0; |
| 230 | + |
| 231 | + for (auto it = mp.begin(); it != mp.end(); ++it) { |
| 232 | + int n = it->second; |
| 233 | + ans += (n * (n - 1)) / 2; // total tuples |
| 234 | + } |
| 235 | + |
| 236 | + return ans * 8; |
| 237 | + } |
| 238 | +}; |
| 239 | +
|
| 240 | + ``` |
| 241 | +</TabItem> |
| 242 | +</Tabs> |
| 243 | + |
| 244 | + </TabItem> |
| 245 | +</Tabs> |
| 246 | + |
| 247 | +## References |
| 248 | + |
| 249 | +- **LeetCode Problem**: [Tuple With Same Product](https://leetcode.com/problems/tuple-with-same-product/description/) |
| 250 | + |
| 251 | +- **Solution Link**: [LeetCode Solution](https://leetcode.com/problems/tuple-with-same-product/solutions) |
| 252 | + |
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