Count the Good Pairs
Easy
array
counting
Problem Description
Find the number of pairs (i,j) where nums[i] == nums[j] and i < j. Count all such valid pairs in the array.
Input Format
First line contains n (array size). Second line contains n integers separated by spaces.
Output Format
A single integer representing the number of good pairs.
Constraints
1 <= n <= 100
1 <= nums[i] <= 100
Sample Input/Output
Input:
4 1 2 3 1
Output:
1
Explanation
There is one good pair: (0,3) where nums[0] = nums[3] = 1 and 0 < 3.
Solution Hints
- Read carefully: Understand input/output format and constraints
- Start simple: Think of brute force solution first, then optimize
- Edge cases: Consider empty inputs, single elements, max constraints
- Data structures: Choose arrays, hash maps, sets based on problem needs
- Time complexity: Ensure your solution fits within time limits
- Test examples: Verify logic with provided sample inputs
75
Points
Points
2000ms
Time Limit
Time Limit
256MB
Memory Limit
Memory Limit
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