n-repeated-element-in-size-2n-array.go

// You are given an integer array nums with the following properties:
//
//
// 	nums.length == 2 * n.
// 	nums contains n + 1 unique elements.
// 	Exactly one element of nums is repeated n times.
//
//
// Return the element that is repeated n times.
//
//  
// Example 1:
// Input: nums = [1,2,3,3]
// Output: 3
// Example 2:
// Input: nums = [2,1,2,5,3,2]
// Output: 2
// Example 3:
// Input: nums = [5,1,5,2,5,3,5,4]
// Output: 5
//
//  
// Constraints:
//
//
// 	2 <= n <= 5000
// 	nums.length == 2 * n
// 	0 <= nums[i] <= 104
// 	nums contains n + 1 unique elements and one of them is repeated exactly n times.
//
//


func repeatedNTimes(A []int) int {
    m := make(map[int]int)
    for _, v := range A {
        m[v]++
        if m[v] > 1 {
            return v
        }
    }
    return 0
}