Rabbits & Foxes

The task is to calculate the populations of foxes and rabbits who live within a certain area of land, as that number changes from year to year. The rabbit and fox populations are controlled by the following formulas:

rabbitsNext = rabbitsPrev + (int)Math.Round(rabbitsPrev * rabbitBirthRate) - (int)Math.Round(rabbitsPrev * foxesPrev * foxKillRate)

foxesNext = foxesPrev + (int)Math.Round(foxesPrev * rabbitsPrev * foxBirthRate) - (int)Math.Round(foxesPrev * foxDeathRate)

where

• rabbitsNext is the rabbit population for the next year
• rabbitsPrev is the rabbit population of the previous year
• rabbitBirthRate is the birth rate of rabbits
• foxKillRate is the death rate of rabbits, dependent on # of foxes
• foxesNext is the fox population for the next year
• foxesPrev is the fox population of the previous year
• foxBirthRate is the birth rate of foxes, dependent on # of rabbits
• foxDeathRate death rate of foxes, caused naturally

The task is for the given initial populations and growth parameters and number of years, calculate the year-by-year changes.

Note: Since the fox and rabbit populations should be integers, so you will have convert the result of the calculation to int.

Example: for the following input values:

int rabbits = 100;
double rabbitBirthRate = 0.2;
double foxKillRate = 0.005;
int foxes = 10;
double foxBirthRate = 0.001;
double foxDeathRate = 0.2;

the output should look like this:

Year 0. Rabbits: 100, Foxes: 10
Year 1. Rabbits: 115, Foxes: 9
Year 2. Rabbits: 133, Foxes: 8
Year 3. Rabbits: 155, Foxes: 7
Year 4. Rabbits: 181, Foxes: 7
Year 5. Rabbits: 211, Foxes: 7
Year 6. Rabbits: 246, Foxes: 7
Year 7. Rabbits: 286, Foxes: 8
Year 8. Rabbits: 332, Foxes: 8
Year 9. Rabbits: 385, Foxes: 9
Year 10. Rabbits: 445, Foxes: 10

What happens when you increase the number of years?