1442. 形成两个异或相等数组的三元组数目

/**
 * @param {number[]} arr
 * @return {number}
 */
var countTriplets = function(arr) {
    let n = arr.length;
    let dp = new Array(n).fill(0);
    let res = [];
    let count=0;
    for(let i = 0;i<n;i++){
        dp[i] = (i==0?0:dp[i-1]) ^ arr[i];
        if(dp[i] == 0){
            res.push({‘i‘:0,‘k‘:i});
        }
    }
    for(let i=0;i<n;i++){
        for(let j=i+1;j<n;j++){
            if((dp[i]^dp[j]) === 0){
                res.push({‘i‘:i+1,‘k‘:j});
            }
        }
    }
    while(res.length>0){
        let cur = res.pop();
        for(let j=cur.i+1;j<=cur.k;j++){
            let left = (cur.i === j-1)?(dp[cur.i]^dp[cur.i-1]):(dp[cur.i-1]^dp[j-1]);
            let right = (cur.k===j)?(dp[cur.k]^dp[cur.k-1]):(dp[cur.k]^dp[j-1]);
            if( left === right){
                count++;
            }
        }
    }
    return count;
};
let arr = [2,3,1,6,7]
console.log(arr, countTriplets(arr))
arr = [1,1,1,1,1]
console.log(arr, countTriplets(arr))
arr =[2,3]
console.log(arr, countTriplets(arr))
arr = [1,3,5,7,9]
console.log(arr, countTriplets(arr))
arr = [7,11,12,9,5,2,7,17,22]
console.log(arr, countTriplets(arr))