What does this sentence mean? "the total number of unique rentals they have made". Should inventory_id be different? But this column wasn't mentioned in (data that is needed for the task). Some rental has more than one payment. Should we sum them?

L Q Q c U B N
0 -> 2 -> 4 -> 16 -> (copy = 16) -> 4 -> -12 (=255) -> output 255
expected:<2[44]> but was:<2[55]>
Where did I make a mistake?

del

I get this answer:
Test Results:
Random Tests
cost -- random
Test Passed
Test Passed
Test Passed
Test Passed
Test Passed
Test Passed
Test Passed
Test Passed
Test Passed
Test Passed
make_min_tree -- random
Test Passed
Test Passed
STDERR
Execution Timed Out (12000 ms)

How can I understans what is going on?

PowerShell.
What is a mistake:
Expected: {0 0.99 0.14 -0.98 -0.28 0.93 0.41 -0.88 -0.54 0.8 0.65 -0.72}
But was: {0 0.99 0.14 -0.98 -0.28 0.93 0.41 -0.88 -0.54 0.8 0.65 -0.72}
?

I try with Powershell:
Expected string length 231 but was 238. Strings differ at index 25.
Expected: {Original Balance: 1000.00\n125 Market 125.45 Balance 874.55\n126 Hardware 34.95 Balance 839.60\n127 Video 7.45 Balance 832.15\n128 Book 14.32 Balance 817.83\n129 Gasoline 16.10 Balance 801.73\nTotal expense 198.27\nAverage expense 39.65}
But was: {Original Balance: 1000.00\n125 Market 125.45 Balance 874.55\n126 Hardware 34.95 Balance 839.60\n127 Video 7.45 Balance 832.15\n128 Book 14.32 Balance 817.83\n129 Gasoline 16.10 Balance 801.73\nTotal expense 198.27\nAverage expense 39.65}

Expected string length 269 but was 277. Strings differ at index 22.
Expected: {Original Balance: 1822\n122 Hairdresser 128.00 Balance 1694.00\n139 Picture 17.6 Balance 1676.40\n130 Stamps 24.8 Balance 1651.60\n128 Pen 3.2 Balance 1648.40\n003 Market 19.00 Balance 1629.40\n160 Vegetables 11.00 Balance 1618.40\nTotal expense 203.60\nAverage expense 33.93}
But was: {Original Balance: 1822\n122 Hairdresser 128.00 Balance 1694.00\n139 Picture 17.6 Balance 1676.40\n130 Stamps 24.8 Balance 1651.60\n128 Pen 3.2 Balance 1648.40\n003 Market 19.00 Balance 1629.40\n160 Vegetables 11.00 Balance 1618.40\nTotal expense 203.60\nAverage expense 33.93}

Where is the difference? I compared it symbol by symbol.

Is it possible to create algoritm less than n^2?

What does it mean:
Test Results:
diagonal
Fixed Tests
Should Pass Fixed Tests
Expected: {101}
But was: {101}
Stack Trace
Completed in 756ms
Completed in 756ms
Random Tests
Should pass Random Tests
Expected: {2760681}
But was: {2760681}
I try to use PowerShell, but can't pass the test.

I see for PowerShell:
14 of 11,796
Is it possible to pass this kata in PS?