sumContainsTarget.js

// Write an algorithm to check if the sum of any two elements in an 
// array/list matches a given target, and return their indexes in 
// an array.
//
// Parameters: [0, 6, 8, 4], 10
// Result:     [ 1, 3]
// Parameters: [20, 18,  5,  4, 10, 22], 42  
// Result:     [ 0, 5]


const sumContainsTarget = (arr = [] , target ) => {
  const params = {};
  
  for(let i = 0; i< arr.length; i++) {
    params[arr[i]] = i
  }
  
  for( let i  = 0; i < arr.length; i++) {
    const nextNumber = target - arr[i]; 
    if(params[nextNumber]) {
      return [i, params[nextNumber]]
    }
  } 
  
  return [];
}


const result = sumContainsTarget([0, 6, 8, 4], 10);

console.log(result);