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86d333ee94
* chore: Switch to Node 20 + Vitest * chore: migrate to vitest mock functions * chore: code style (switch to prettier) * test: re-enable long-running test Seems the switch to Node 20 and Vitest has vastly improved the code's and / or the test's runtime! see #1193 * chore: code style * chore: fix failing tests * Updated Documentation in README.md * Update contribution guidelines to state usage of Prettier * fix: set prettier printWidth back to 80 * chore: apply updated code style automatically * fix: set prettier line endings to lf again * chore: apply updated code style automatically --------- Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com> Co-authored-by: Lars Müller <34514239+appgurueu@users.noreply.github.com>
66 lines
2.0 KiB
JavaScript
66 lines
2.0 KiB
JavaScript
/**
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* @function powLinear
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* @description - The powLinear function is a power function with Linear O(n) complexity
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* @param {number} base
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* @param {number} exponent
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* @returns {number}
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* @example - powLinear(2, 2) => 4 --> 2 * 2
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* @example - powLinear(3, 3) => 27 --> 3 * 3 * 3
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*/
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const powLinear = (base, exponent) => {
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if (exponent < 0) {
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base = 1 / base
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exponent = -exponent
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}
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let result = 1
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while (exponent--) {
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// Break the execution while the exponent will 0
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result *= base
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}
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return result
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}
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/**
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* @function powFaster
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* @description - The powFaster function is a power function with O(logN) complexity
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* @param {number} base
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* @param {number} exponent
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* @returns {number}
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* @example - powFaster(2, 2) => 4 --> 2 * 2
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* @example - powFaster(3, 3) => 27 --> 3 * 3 * 3
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*/
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const powFaster = (base, exponent) => {
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if (exponent < 2) {
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// explanation below - 1
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return base && ([1, base][exponent] || powFaster(1 / base, -exponent))
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}
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if (exponent & 1) {
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// if the existing exponent is odd
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return base * powFaster(base * base, exponent >> 1) // explanation below - 2
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}
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return powFaster(base * base, exponent / 2)
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}
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/**
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* 1 - Magic of short circuit evaluation (&&, ||)
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* if the base is 0 then it returns 0 cause 0 is falsy
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* if the base is not 0 then it's must be truthy. after that, it will be executed the right portion of the && (AND) operator
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* Now it checks the exponent by the help array index, is it 0 or 1.
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* if the exponent is not 0 or 1 it's definitely less than 0, and a negative number is not a valid index number so it returns "undefined"
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* if the expression is undefined mean -> falsy, the || (OR) operator evaluates the right portion that is a recursive function.
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*/
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/**
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* 2 - Play with right shift bitwise operator (>>)
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* right shift with any odd numbers it returns the floor number instead of float.
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* E.g. if the number is 5, after right shifting with 1 it's will give us 2, not 2.5
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* cause the right shift formula is --> x >> y = |x| / 2^y
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*/
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export { powLinear, powFaster }
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