$"""$

You are working for a promising new stock trading startup called "AlgoStreet."

You have been tasked with developing a new trading signal that will be incorporated into the

automatic trading strategy. A new metric has been introduced called

positive stock pressure, which measures how many consecutive days before today $($not includ$-$

ing today$)$ have a higher price.

You will be given daily stock prices for the last N days and must return the list of daily positive

stock pressures for each day.

Below is an example for $1$ week of data.

$|$ Price $|$ Stock Pressure

$------------------------------$

$|$ Day $1|100|1$

$------------------------------$

$|$ Day $2|90|2$

$------------------------------$

$|$ Day $3|95|1$

$------------------------------$

$|$ Day $4|100|1$

$-------------------------------$

$|$ Day $5|105|1$

$-------------------------------$

$|$ Day $6|110|1$

$-------------------------------$

$|$ Day $7|80|7$

$-------------------------------$

Implement the function to compute stock pressure.

To compute positive stock pressure for each stock price, you should find the last day with the

lower $($or equal$)$ price. In other words, the positive stock pressure is the number of days since the

last day with a lower or equal price.

You must solve this problem by using a stack as the primary data structure.

Code Author:

Running Time Analysis of compute$\_$pressure

$--------------------$

$"""$

def compute$\_$pressure$($stock$\_$history: list$)$:

n $=$ len$($stock$\_$history$)$

pressures $=[0]*$ n

stack $=[]$

for i in range$($n$)$:

while stack and stock$\_$history$[$stack$[-1]]<=$ stock$\_$history$[$i$]$:

stack.pop$()$

if not stack:

pressures$[$i$]=$ i $+1$

else:

pressures$[$i$]=$ i $-$ stack$[-1]$

stack.append$($i$)$

return pressures

class TestGeneratePressure:

def run$\_$unit$\_$tests$($self$)$:

self.test$\_$example$()$

self.test$\_2()$

self.test$\_3()$

self.test$\_$no$\_$days$\_$provided$()$

self.test$\_$large$\_$list$()$

self.test$\_$repeating$\_$prices$()$

def print$\_$test$\_$result$($self$,$ test$\_$name, result$)$:

color $="\backslash 033[92$m$"$ if result else $"\backslash 033[91$m$"$

reset $="\backslash 033[0$m$"$

print$($f$"\{$color$\}[\{$result$\}]\{$test$\_$name$\}\{$reset$\}")$

def test$\_$answer$($self$,$ test$\_$name, result, expected$)$:

if result $==$ expected:

self.print$\_$test$\_$result$($test$\_$name, True$)$

else:

self.print$\_$test$\_$result$($test$\_$name, False$)$

print$($f$"$Expected: $\{$expected$\}$

Got: $\{$result$\}")$

def test$\_$example$($self$)$:

stock$\_$history $=[100,90,95,100,105,110,80]$

result $=$ compute$\_$pressure$($stock$\_$history$)$

expected$\_$answer $=[1,2,1,1,1,1,7]$

self.test$\_$answer$("$test$\_$example", result, expected$\_$answer$)$

def test$\_2($self$)$:

stock$\_$history $=[80,74,75,90,120,81]$

result $=$ compute$\_$pressure$($stock$\_$history$)$

expected$\_$answer $=[1,2,1,1,1,3]$

self.test$\_$answer$("$test$\_2",$ result, expected$\_$answer$)$

def test$\_3($self$)$:

stock$\_$history $=[1,2,5,10,12,20]$

result $=$ compute$\_$pressure$($stock$\_$history$)$

expected$\_$answer $=[1,1,1,1,1,1]$

self.test$\_$answer$("$test$\_3",$ result, expected$\_$answer$)$

def test$\_$no$\_$days$\_$provided$($self$)$:

stock$\_$history $=[]$

result $=$ compute$\_$pressure$($stock$\_$history$)$

expected$\_$answer $=[]$

self.test$\_$answer$("$test$\_$no$\_$days$\_$provided", result, expected$\_$answer$)$

def test$\_$large$\_$list$($self$)$:

stock$\_$history $=[100,90,80,85,90,95,100,105,110,120,140,120,100,80]$

result $=$ compute$\_$pressure$($stock$\_$history$)$

expected$\_$answer $=[1,2,3,1,1,1,1,1,1,1,1,2,6,11]$

self.test$\_$answer$("$test$\_$large$\_$list", result, expected$\_$answer$)$

def test$\_$repeating$\_$prices$($self$)$:

stock$\_$history $=[10,10,10]$

result $=$ compute$\_$pressure$($stock$\_$history$)$

expected$\_$answer $=[1,1,1]$

self.test$\_$answer$("$test$\_$repeating$\_$prices", result, expected$\_$answer$)$

if $\_\_$name$\_\_==\text{'}\_\_$main$\_\_\text{'}$:

test$\_$runner $=$ TestGeneratePressure$()$

test$\_$runner.run$\_$unit$\_$tests$()$

The formula for calculating positive stock pressure is: day $-$ last day wirh smaller or equal price

Day $1$: $1-0=1$

Day $2$: $2-0=2$

Day $3$: $3-2=1$

Day $4$: $4-3=1$

Day $5$: $5-4=1$

Day $6$: $6-5=1$

Day $7$: $7-0=7$