JavaScript Prefix Sum Function

prefixsum.js

  function prefixSum(A) {
    var i = 0,
        l = A.length,
        P = new Array(l),
        sum = A[0];

    P[0] = sum;

    while (++i < l) {
      sum += A[i];
      P[i] = sum;
    }

    return P;
}