Acid
104 lines
2.2 KiB
Go
104 lines
2.2 KiB
Go
package tests
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import (
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"testing"
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"datastructures/algo"
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)
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// --- basic profit cases ---
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func TestMaxSubarray_BasicProfit(t *testing.T) {
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// buy at 1, sell at 6 → 5
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got := algo.MaxSubarray([]int{7, 1, 5, 3, 6, 4})
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if got != 5 {
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t.Errorf("expected 5, got %d", got)
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}
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}
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func TestMaxSubarray_ProfitAtEnd(t *testing.T) {
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// buy at 1, sell at 9 → 8
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got := algo.MaxSubarray([]int{3, 1, 4, 1, 5, 9})
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if got != 8 {
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t.Errorf("expected 8, got %d", got)
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}
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}
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func TestMaxSubarray_AlreadySorted(t *testing.T) {
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// buy at 1, sell at 5 → 4
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got := algo.MaxSubarray([]int{1, 2, 3, 4, 5})
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if got != 4 {
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t.Errorf("expected 4, got %d", got)
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}
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}
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// --- no profit cases ---
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func TestMaxSubarray_StrictlyDecreasing(t *testing.T) {
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// prices only fall; no profitable trade
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got := algo.MaxSubarray([]int{5, 4, 3, 2, 1})
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if got != 0 {
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t.Errorf("expected 0, got %d", got)
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}
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}
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func TestMaxSubarray_AllSame(t *testing.T) {
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got := algo.MaxSubarray([]int{3, 3, 3, 3})
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if got != 0 {
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t.Errorf("expected 0, got %d", got)
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}
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}
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// --- single element ---
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func TestMaxSubarray_SingleElement(t *testing.T) {
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got := algo.MaxSubarray([]int{42})
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if got != 0 {
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t.Errorf("expected 0, got %d", got)
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}
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}
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// --- two elements ---
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func TestMaxSubarray_TwoElementsProfit(t *testing.T) {
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got := algo.MaxSubarray([]int{1, 10})
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if got != 9 {
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t.Errorf("expected 9, got %d", got)
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}
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}
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func TestMaxSubarray_TwoElementsLoss(t *testing.T) {
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got := algo.MaxSubarray([]int{10, 1})
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if got != 0 {
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t.Errorf("expected 0, got %d", got)
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}
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}
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// --- minimum appears late ---
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func TestMaxSubarray_MinInMiddle(t *testing.T) {
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// dip to 2 at index 3, then rises to 8
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got := algo.MaxSubarray([]int{5, 4, 3, 2, 8})
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if got != 6 {
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t.Errorf("expected 6, got %d", got)
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}
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}
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// --- negative values ---
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func TestMaxSubarray_AllNegative(t *testing.T) {
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// minimum tracks most negative; no positive spread possible
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got := algo.MaxSubarray([]int{-5, -3, -1})
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if got != 4 {
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t.Errorf("expected 4, got %d", got)
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}
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}
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func TestMaxSubarray_MixedNegativePositive(t *testing.T) {
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// buy at -3, sell at 5 → 8
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got := algo.MaxSubarray([]int{2, -3, 1, 5})
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if got != 8 {
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t.Errorf("expected 8, got %d", got)
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}
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}
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