boomerang.js

function findBoomrangs(arr){
    let count = 0;
for(let i=0; i<arr.length-2;i++){

        if(arr[i] == arr[i+2]){
            count = count +1;
        }


    }
    return count;
}
console.log(findBoomrangs([1, 7, 1, 7, 1, 7, 1]));