How to get a chicken and a rabbit in the same cage in JavaScript

In mathematics, the chicken and rabbit problem is a classic application problem. This problem describes two animals, chickens and rabbits, placed in the same cage. Given the total number of animals and the total number of legs, find the number of chickens and rabbits. In computer programming languages, this problem is also often used to practice algorithms. In JavaScript language, we can solve the problem of chicken and rabbit in the same cage by writing code.

Problem Description

Suppose there are x chickens and y rabbits in a cage, a total of n animals, and a total of m legs. The question now is: How to use JavaScript program to solve the values ​​of x and y?

Solution

Use mathematical formulas to solve

Let’s first look at the solution to the problem of chicken and rabbit in the same cage. If we assume that the chicken has a leg and the rabbit has b legs, then according to the meaning of the question, we can set up the following equation:

ax by = m (1)

x y = n (2)

We can solve the chicken and rabbit problem by solving the solution of this system of equations. Now, let's take a look at how to solve this system of equations.

First, we express the variable x of the first formula as a function of y, and get:

x = (m - b*y) / a

Then we Putting the above equation into the second formula, we get:

(m - b*y) / a y = n

By moving terms and simplifying, we can get:

y = (m - a*n) / (b - a)

x = n - y

Use code to solve

Use mathematical formulas It is very easy to solve the problem of chicken and rabbit in the same cage. But when actually writing a JavaScript program, we need to convert the above mathematical formula into code form so that it can be used in the computer.

The following is a JavaScript code to solve the problem of chicken and rabbit in the same cage:

function chickenAndRabbit(total, legs) {
    let rabbit = (legs - 2 * total) / 2;
    let chicken = total - rabbit;
    if (rabbit >= 0 && chicken >= 0 && rabbit % 1 == 0) {
        console.log("There are " + chicken + " chickens and " + rabbit + " rabbits in the cage.");
    }
    else {
        console.log("There is no solution to the problem.");
    }
}

chickenAndRabbit(10, 32);

The 'chickenAndRabbit' function in this code can receive two parameters: the total number and the number of legs. The function first calculates the number of rabbits and chickens, and then determines whether the calculated number is a positive integer. If so, output the number of chickens and rabbits, otherwise output an error message.

In the above code, we need to pay attention to the following points:

• We first use x to represent the number of chickens, and y to represent the number of rabbits, and according to the equation system (1) and (2) find the values ​​of x and y.
• We need to check whether the calculated number of rabbits and chickens is a positive integer to ensure the correctness of the answer.
• We use the console.log() function to output the results.

Summary

The chicken and rabbit in the same cage problem is one of the more classic problems in computer programming. By using mathematical formulas and JavaScript code, we can easily calculate the number of chickens and rabbits. In the actual programming process, we need to pay attention to check whether the results we calculate are consistent with the actual situation to ensure the correctness of the program.

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