Selection Sort

Finds the minimum element in the unsorted region and swaps it into the next sorted position.

0 elements

SpdSize50

>Ready — Selection Sort

Code

for (let i = 0; i < length - 1; i++) {
  let minIdx = i;
  for (let j = i + 1; j < length; j++) {
    if (compare(minIdx, j)) {
      minIdx = j;
    }
  }
  if (minIdx !== i) {
    swap(i, minIdx);
  }
}

for (let i = 0; i < length - 1; i++) {
  let minIdx = i;
  for (let j = i + 1; j < length; j++) {
    if (compare(minIdx, j)) {
      minIdx = j;
    }
  }
  if (minIdx !== i) {
    swap(i, minIdx);
  }
}

Analysis

BEST O(n²)

AVG O(n²)

WORST O(n²)

SPACE O(1)

UNSTABLE

Selection Sort divides the array into sorted and unsorted regions. Each pass scans the unsorted region for the smallest element, then swaps it into the next sorted position. Always makes O(n²) comparisons regardless of input order.

Edit in playground→