20/10/09 14:14:59.57 /NdRCF04.net
>>634 js 改善
function quadratic(a, b, c) {
const rt = Math.sqrt(b ** 2 - 4 * a * c)
return [(-b + rt) / (2 * a), (-b - rt) / (2 * a)]
}
function quadraticReal(...abc) {
const ans = quadratic(...abc)
const [a1, a2] = ans
if (isNaN(a1)) return []
if (a1 === a2) return [a1]
return ans
}
const quadraticRealWithCount = (...abc) => addCount(quadraticReal(...abc))
const addCount = a => [a, a.length]
console.log(quadraticRealWithCount(3, -2, -1))
// [ [ 1, -0.3333333333333333 ], 2 ]
console.log(quadraticRealWithCount(3, 6, 3))
// [ [ -1 ], 1 ]
console.log(quadraticRealWithCount(1, 2, 3))
// [ [], 0 ]