for (i = 0; i < n-1; ++i) {
    min = i;
    for (j = i+1; j < n; ++j)
        if (a[j] < a[min]) min = j;
    swap(a[i], a[min]);
}

Outer loop: #iter = n-1   C_body  =  C₌ + C_for + C_swap

Inner loop: #iter = n-1 + n-2 + ... + 1 = n(n-1)/2 = (n²-n)/2

Cost:    (n²-n)/2 × C_< + n-1 × (C₌ + C_swap)  ⇒  O(n²)