Using Counted loops with list for this scenario

Question

Suppose there is an island with two rabbits (male and female). Every 30 days, the population of rabbits doubles. Write a program that has the user input the number of days and then calculate the new population. Use a counted loop.

Extension:

(a) Let the user specify the initial population of the island.

(b) Let the user specify how many days it takes for the population to double.

 

Answer 1

In C++:

#include <iostream>

using namespace std;

int main(int argc, char **argv) {

int population = 2;

int daysToDouble = 30;

if (argc < 2) {

cout << "Usage: " << argv[0]

<< " <number_of_days> [initial_population] [days_to_double]" << endl;

cout << endl;

cout << "[initial_population] and [days_to_double] will default to 2 and "

"30, respectively, if not provided"

<< endl;

return 0;

}

int days = atoi(argv[1]);

if (argc > 2) {

population = atoi(argv[2]);

}

if (argc > 3) {

daysToDouble = atoi(argv[3]);

}

for (int i = 0; i < days / daysToDouble; i++) {

population *= 2;

}

cout << population << endl;

return 0;

}

And the sample output:

> g++ -o main main.cpp

> ./main

Usage: ./main <number_of_days> [initial_population] [days_to_double]

[initial_population] and [days_to_double] will default to 2 and 30, respectively, if not provided

> ./main 10

2

> ./main 30

4

> ./main 60

8

> ./main 60 4

16

> ./main 60 4 15

64

Answer 2

# Using Python:

def defaultPopulation(totalDays):

population = 2

for doubles in range( totalDays // 30 ):

population *= 2

return population

def populationWithInitial(initial, totalDays):

population = initial

for doubles in range( totalDays // 30 ):

population *= 2

return population

def populationWithDaysToDouble(daysToDouble, totalDays):

population = 2

for doubles in range( totalDays // daysToDouble ):

population *= 2

return population