### Odd Occurrences In Array

January 16, 2020

**Write a function:**

function solution(A);

that, given an array A consisting of N integers, returns the value of the **unpaired** element.

For example, given array A such that:

A[0] = 9

A[1] = 3

A[2] = 9

A[3] = 3

A[4] = 9

A[5] = 7

A[6] = 9

the function should return 7.

Write an efficient algorithm for the following assumptions:

• N is an odd integer within the range [1..1,000,000];

• each element of array A is an integer within the range [1..1,000,000,000];

• **all but one** of the values in A occur an even number of times.

```
function solution(A) {
// write your code in JavaScript (Node.js 8.9.4)
A.sort()
for(let i=0; i<A.length; i+=2){
if(A[i]!=A[i+1]) return A[i]
}
return A[A.length-1]
}
console.log("solution([9,3,9,3,9,7,9]): ", solution([9,3,9,3,9,7,9]))
```