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Discussion on: Daily Challenge #154 - Stable Arrangement

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centanomics profile image
Cent

JS, had to google how to use a reducer for this one since it was simpler than my original idea to add all of the values

CodePen


const solver = (arr, n, q) => {
  // console.log("Welcome to the stable arrangment, your quota is:", q)
  for(let i = 0; i < arr.length - n + 1; i++) {
    let j = 0;
    do {
      const set = arr.slice(i, i+n).reduce((acc, val) => acc + val);
      if(set > q) {
        let value = arr.shift();
        arr.push(value);
      } else {
        // console.log(arr.slice(i, i+n),set);
        break;
      }
    } while(true);
  }
  return arr;
}

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nickholmesde profile image
Nick Holmes

Your "shift then push" approach changes the positions of the values in the array, but not their order. Conceptually, (shift then push) * length gets you back were you started.

As the task asks you to "rearrange" the values, which I take to mean "change the order" of the values, and you are not changing the order, it would seem that this approach cannot work in the general case.

For example, in the case of

solver([3,5,7,1,6,8,2,4], 3, 13);

the return value is

[7,1,6,8,2,4,3,5]

This is clearly the input rotated 2 to the left, and the first slice [7, 1, 6] sums to 14 (when it should be <= 13).

(In the worst case, where no slice of the input sums <= q, your function will run forever).