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@detunized detunized/index.js
Last active Mar 1, 2019

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JavaScript solutions profiling
#!/usr/bin/env node --expose-gc
//
// Logest word
//
function findLongestWordLengthForLoop(str) {
let maxVal = 0;
const wordArr = str.split(' ');
for(let i = 0; i < wordArr.length; i++) {
let word = wordArr[i];
if (word.length > maxVal) {
maxVal = word.length;
}
}
return maxVal;
}
function findLongestWordLengthForEach(str) {
let maxVal = 0;
const wordArr = str.split(' ');
wordArr.forEach(word => {
if (word.length > maxVal) {
maxVal = word.length;
}
});
return maxVal;
}
function findLongestWordLengthOriginal(str) {
const arrOfWords = str.split(' ');
const arrOfLengths = arrOfWords.map(item => item.length);
return Math.max(...arrOfLengths);
}
function findLongestWordLengthFixed(str) {
const arrOfWords = str.split(' ');
const arrOfLengths = arrOfWords.map(item => item.length);
let maxLength = 0;
for (let i = 0; i < arrOfLengths.length; ++i) {
if (arrOfLengths[i] > maxLength) {
maxLength = arrOfLengths[i];
}
}
return maxLength;
}
function findLongestWordLengthFast(str) {
let l = str.length;
let maxLength = 0;
let currentLength = 0;
for (let i = 0; i < l; ++i) {
if (str.charCodeAt(i) === 32) {
if (currentLength > maxLength) {
maxLength = currentLength;
}
currentLength = 0;
} else {
++currentLength;
}
}
// Account for the last word
return currentLength > maxLength ? currentLength : maxLength;
}
//
// Reverse a string
//
function reverseStringSubstring(str) {
let reversedString = '';
for (let i = str.length; i > 0; i--) {
reversedString += str.substring(i, i-1);
}
return reversedString;
}
function reverseStringCharAt(str) {
let reversedString = '';
for (let i = str.length-1; i >= 0; i--) {
reversedString += str.charAt(i);
}
return reversedString;
}
function reverseStringSplitJoin(str) {
return str.split('').reverse().join('');
}
function reverseStringBuffer(str) {
let b = Buffer.from(str, "ascii");
for (let i = 0, n = str.length; i < n / 2; i++) {
let t = b[i];
b[i] = b[n - 1 - i];
b[n - 1 - i] = t;
}
return b.toString("ascii");
}
function reverseStringBufferReverse(str) {
return Buffer
.from(str, "ascii")
.reverse()
.toString("ascii");
}
//
// Plumbing
//
function timeIt(label, fs) {
const runs = 10;
let totals = [];
for (let f = 0; f < fs.length; ++f) {
global.gc();
totals[f] = 0.0;
for (let i = 0; i < runs; ++i) {
try
{
let start = process.hrtime();
fs[f]();
let duraton = process.hrtime(start);
totals[f] += duraton[1] / 1000000.0;
}
catch (e)
{
totals[f] = NaN;
}
}
}
console.info("%s" + "\t%f".repeat(fs.length), label, ...totals.map(total => total / runs));
}
for (let i = 0; i < 1000000; i += 10000) {
let str = "a" + " a".repeat(i / 2);
let length = str.length;
if (0)
timeIt(length, [
() => reverseStringSubstring(str),
() => reverseStringCharAt(str),
() => reverseStringSplitJoin(str),
() => reverseStringBuffer(str),
() => reverseStringBufferReverse(str),
]);
if (0)
timeIt(length, [
() => findLongestWordLengthForLoop(str),
() => findLongestWordLengthForEach(str),
() => findLongestWordLengthOriginal(str),
() => findLongestWordLengthFixed(str),
() => findLongestWordLengthFast(str),
]);
}
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