skrrrrt

linked.js

function solution(A) {
  const { total } = A.reduce(
    ({ position, total }, _, _idx, arr) => {
      const val = arr[position];

      if (val !== -1) {
        return {
          position: arr[position],
          total: total + 1,
        };
      }

      return { position, total };
    },
    { position: 0, total: 1 }
  );
  return total;
}

paired.js

const limit = 1000000000;
function solution(A) {
  // Get count of each number
  const count = A.reduce(
    (acc, curr) => ({
      ...acc,
      [curr]: acc[curr] ? acc[curr] + 1 : 1,
    }),
    {}
  );

  return Object.keys(count).reduce((acc, curr) => {
    if (acc >= limit) {
      return limit;
    }
    const currentIndicie = count[curr];
    const add = (currentIndicie * (currentIndicie - 1)) / 2;
    return acc + add;
  }, 0);
}