param-io.tech-assignemnt.js

var temp = [1, 2, 4, 5, 6, 8, 2, 7, 2];
var encountered = [];


function f(a) {
  let min = -1;
  for (let i = 0; i < a.length; i++) {
    let id = i + 1;
    while (id !== 0) {
      id = a.indexOf(a[i], id) + 1;
      const diff = (id - 1) - i;
      min = (diff >= 0 && (diff < min || min === -1)) ? diff : min;
    }
  }
  return min;
}

console.log(f(temp));