Sorting / ComparisonSelection SortEasy

Selection Sort — Select Minimum, Swap to Position

Find the minimum in the unsorted region, swap it to the front. Repeat. Always O(N²).

Selection Sort — Comparison Sort
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Practice on GeeksforGeeks: Selection Sort
Open Problem

How it works

Scan the unsorted portion to find the minimum. Swap it with the first unsorted element. The sorted boundary moves right by one each pass.

Key Property

// Always exactly N-1 swaps
// Minimizes number of swaps
for i = 0 to n-2:
  minIdx = findMin(arr, i, n)
  swap(arr[i], arr[minIdx])
Interactive Visualization
Scanning
Current Min
Swapping
Sorted
Array
Bar Chart
Step 0 of 0
Current Min
—
Comparisons
0
Swaps
0
Sorted
0
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✓ Sorted
Speed
C++ — Selection Sort
void selectionSort(vector<int>& arr) {
    int n = arr.size();
    for (int i = 0; i < n - 1; i++) {
        int minIdx = i;
        for (int j = i + 1; j < n; j++) {
            if (arr[j] < arr[minIdx])
                minIdx = j;
        }
        swap(arr[i], arr[minIdx]);
    }
}
Complexity
Time (All Cases)
O(N²)

Always scans remaining elements.

Space
O(1)

In-place sort.

Stable?
No

Swaps can change relative order of equal elements.

Swaps
O(N)

At most N-1 swaps. Best for minimizing writes.

📝 Notes

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