/**
* @param {number[]} arr
* @return {number}
*/
var countTriplets = function (arr) {
let n = arr.length
let prefix = new Array(n + 1).fill(0)
for (i = 0; i < n; i++) {
prefix[i + 1] = prefix[i] ^ arr[i]
}
let count = 0
for (let i = 0; i < n; i++) {
for (let k = i + 1; k < n; k++) {
if (prefix[i] === prefix[k + 1]) {
count += (k - i)
}
}
}
return count
};
#1442. Count Triplets That Can Form Two Arrays of Equal XOR
![](https://media.dev.to/cdn-cgi/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https%3A%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F1033633%2F7ecb4d45-cef8-48ae-9083-c7551666fa32.jpg)