flying-hero
96f6318101
新增: - backend/venv/ - Python 虚拟环境 - backend/start.sh - 启动脚本（使用虚拟环境） - backend/requirements.txt - 依赖列表 - .gitignore - 忽略虚拟环境和缓存文件 说明: - 每个项目使用独立虚拟环境 - 避免依赖冲突 - 启动脚本自动创建和激活虚拟环境
25 lines
869 B
JavaScript
25 lines
869 B
JavaScript
/*
|
|
Given the ratio a : b : c = 2 : 3 : 4
|
|
What is c, given a = 40?
|
|
|
|
A general ratio chain is a_1 : a_2 : a_3 : ... : a_n = r_1 : r2 : r_3 : ... : r_n.
|
|
Now each term can be expressed as a_i = r_i * x for some unknown proportional constant x.
|
|
If a_k is known it follows that x = a_k / r_k. Substituting x into the first equation yields
|
|
a_i = r_i / r_k * a_k.
|
|
|
|
Given an array r and a given value a_k, the following function calculates all a_i:
|
|
*/
|
|
|
|
function calculateRatios(r, a_k, k) {
|
|
const x = Fraction(a_k).div(r[k]);
|
|
return r.map(r_i => x.mul(r_i));
|
|
}
|
|
|
|
// Example usage:
|
|
const r = [2, 3, 4]; // Ratio array representing a : b : c = 2 : 3 : 4
|
|
const a_k = 40; // Given value of a (corresponding to r[0])
|
|
const k = 0; // Index of the known value (a corresponds to r[0])
|
|
|
|
const result = calculateRatios(r, a_k, k);
|
|
console.log(result); // Output: [40, 60, 80]
|