mirror of
https://github.com/krahets/hello-algo.git
synced 2026-08-17 14:10:57 +00:00
Translate all code to English (#1836)
* Review the EN heading format. * Fix pythontutor headings. * Fix pythontutor headings. * bug fixes * Fix headings in **/summary.md * Revisit the CN-to-EN translation for Python code using Claude-4.5 * Revisit the CN-to-EN translation for Java code using Claude-4.5 * Revisit the CN-to-EN translation for Cpp code using Claude-4.5. * Fix the dictionary. * Fix cpp code translation for the multipart strings. * Translate Go code to English. * Update workflows to test EN code. * Add EN translation for C. * Add EN translation for CSharp. * Add EN translation for Swift. * Trigger the CI check. * Revert. * Update en/hash_map.md * Add the EN version of Dart code. * Add the EN version of Kotlin code. * Add missing code files. * Add the EN version of JavaScript code. * Add the EN version of TypeScript code. * Fix the workflows. * Add the EN version of Ruby code. * Add the EN version of Rust code. * Update the CI check for the English version code. * Update Python CI check. * Fix cmakelists for en/C code. * Fix Ruby comments
This commit is contained in:
Yudong Jin
@@ -0,0 +1,74 @@
|
||||
/**
|
||||
* File: iteration.kt
|
||||
* Created Time: 2024-01-25
|
||||
* Author: curtishd (1023632660@qq.com)
|
||||
*/
|
||||
|
||||
package chapter_computational_complexity.iteration
|
||||
|
||||
/* for loop */
|
||||
fun forLoop(n: Int): Int {
|
||||
var res = 0
|
||||
// Sum 1, 2, ..., n-1, n
|
||||
for (i in 1..n) {
|
||||
res += i
|
||||
}
|
||||
return res
|
||||
}
|
||||
|
||||
/* while loop */
|
||||
fun whileLoop(n: Int): Int {
|
||||
var res = 0
|
||||
var i = 1 // Initialize condition variable
|
||||
// Sum 1, 2, ..., n-1, n
|
||||
while (i <= n) {
|
||||
res += i
|
||||
i++ // Update condition variable
|
||||
}
|
||||
return res
|
||||
}
|
||||
|
||||
/* while loop (two updates) */
|
||||
fun whileLoopII(n: Int): Int {
|
||||
var res = 0
|
||||
var i = 1 // Initialize condition variable
|
||||
// Sum 1, 4, 10, ...
|
||||
while (i <= n) {
|
||||
res += i
|
||||
// Update condition variable
|
||||
i++
|
||||
i *= 2
|
||||
}
|
||||
return res
|
||||
}
|
||||
|
||||
/* Nested for loop */
|
||||
fun nestedForLoop(n: Int): String {
|
||||
val res = StringBuilder()
|
||||
// Loop i = 1, 2, ..., n-1, n
|
||||
for (i in 1..n) {
|
||||
// Loop j = 1, 2, ..., n-1, n
|
||||
for (j in 1..n) {
|
||||
res.append(" ($i, $j), ")
|
||||
}
|
||||
}
|
||||
return res.toString()
|
||||
}
|
||||
|
||||
/* Driver Code */
|
||||
fun main() {
|
||||
val n = 5
|
||||
var res: Int
|
||||
|
||||
res = forLoop(n)
|
||||
println("\nFor loop sum result res = $res")
|
||||
|
||||
res = whileLoop(n)
|
||||
println("\nWhile loop sum result res = $res")
|
||||
|
||||
res = whileLoopII(n)
|
||||
println("\nWhile loop (two updates) sum result res = $res")
|
||||
|
||||
val resStr = nestedForLoop(n)
|
||||
println("\nNested for loop traversal result $resStr")
|
||||
}
|
||||
@@ -0,0 +1,78 @@
|
||||
/**
|
||||
* File: recursion.kt
|
||||
* Created Time: 2024-01-25
|
||||
* Author: curtishd (1023632660@qq.com)
|
||||
*/
|
||||
|
||||
package chapter_computational_complexity.recursion
|
||||
|
||||
import java.util.*
|
||||
|
||||
/* Recursion */
|
||||
fun recur(n: Int): Int {
|
||||
// Termination condition
|
||||
if (n == 1)
|
||||
return 1
|
||||
// Descend: recursive call
|
||||
val res = recur(n - 1)
|
||||
// Return: return result
|
||||
return n + res
|
||||
}
|
||||
|
||||
/* Simulate recursion using iteration */
|
||||
fun forLoopRecur(n: Int): Int {
|
||||
// Use an explicit stack to simulate the system call stack
|
||||
val stack = Stack<Int>()
|
||||
var res = 0
|
||||
// Descend: recursive call
|
||||
for (i in n downTo 0) {
|
||||
// Simulate "recurse" with "push"
|
||||
stack.push(i)
|
||||
}
|
||||
// Return: return result
|
||||
while (stack.isNotEmpty()) {
|
||||
// Simulate "return" with "pop"
|
||||
res += stack.pop()
|
||||
}
|
||||
// res = 1+2+3+...+n
|
||||
return res
|
||||
}
|
||||
|
||||
/* Tail recursion */
|
||||
tailrec fun tailRecur(n: Int, res: Int): Int {
|
||||
// Add tailrec keyword to enable tail recursion optimization
|
||||
// Termination condition
|
||||
if (n == 0)
|
||||
return res
|
||||
// Tail recursive call
|
||||
return tailRecur(n - 1, res + n)
|
||||
}
|
||||
|
||||
/* Fibonacci sequence: recursion */
|
||||
fun fib(n: Int): Int {
|
||||
// Termination condition f(1) = 0, f(2) = 1
|
||||
if (n == 1 || n == 2)
|
||||
return n - 1
|
||||
// Recursive call f(n) = f(n-1) + f(n-2)
|
||||
val res = fib(n - 1) + fib(n - 2)
|
||||
// Return result f(n)
|
||||
return res
|
||||
}
|
||||
|
||||
/* Driver Code */
|
||||
fun main() {
|
||||
val n = 5
|
||||
var res: Int
|
||||
|
||||
res = recur(n)
|
||||
println("\nRecursion sum result res = $res")
|
||||
|
||||
res = forLoopRecur(n)
|
||||
println("\nUsing iteration to simulate recursion sum result res = $res")
|
||||
|
||||
res = tailRecur(n, 0)
|
||||
println("\nTail recursion sum result res = $res")
|
||||
|
||||
res = fib(n)
|
||||
println("\nThe ${n}th Fibonacci number is $res")
|
||||
}
|
||||
@@ -0,0 +1,109 @@
|
||||
/**
|
||||
* File: space_complexity.kt
|
||||
* Created Time: 2024-01-25
|
||||
* Author: curtishd (1023632660@qq.com)
|
||||
*/
|
||||
|
||||
package chapter_computational_complexity.space_complexity
|
||||
|
||||
import utils.ListNode
|
||||
import utils.TreeNode
|
||||
import utils.printTree
|
||||
|
||||
/* Function */
|
||||
fun function(): Int {
|
||||
// Perform some operations
|
||||
return 0
|
||||
}
|
||||
|
||||
/* Constant order */
|
||||
fun constant(n: Int) {
|
||||
// Constants, variables, objects occupy O(1) space
|
||||
val a = 0
|
||||
var b = 0
|
||||
val nums = Array(10000) { 0 }
|
||||
val node = ListNode(0)
|
||||
// Variables in the loop occupy O(1) space
|
||||
for (i in 0..<n) {
|
||||
val c = 0
|
||||
}
|
||||
// Functions in the loop occupy O(1) space
|
||||
for (i in 0..<n) {
|
||||
function()
|
||||
}
|
||||
}
|
||||
|
||||
/* Linear order */
|
||||
fun linear(n: Int) {
|
||||
// Array of length n uses O(n) space
|
||||
val nums = Array(n) { 0 }
|
||||
// A list of length n occupies O(n) space
|
||||
val nodes = mutableListOf<ListNode>()
|
||||
for (i in 0..<n) {
|
||||
nodes.add(ListNode(i))
|
||||
}
|
||||
// A hash table of length n occupies O(n) space
|
||||
val map = mutableMapOf<Int, String>()
|
||||
for (i in 0..<n) {
|
||||
map[i] = i.toString()
|
||||
}
|
||||
}
|
||||
|
||||
/* Linear order (recursive implementation) */
|
||||
fun linearRecur(n: Int) {
|
||||
println("Recursion n = $n")
|
||||
if (n == 1)
|
||||
return
|
||||
linearRecur(n - 1)
|
||||
}
|
||||
|
||||
/* Exponential order */
|
||||
fun quadratic(n: Int) {
|
||||
// Matrix uses O(n^2) space
|
||||
val numMatrix = arrayOfNulls<Array<Int>?>(n)
|
||||
// 2D list uses O(n^2) space
|
||||
val numList = mutableListOf<MutableList<Int>>()
|
||||
for (i in 0..<n) {
|
||||
val tmp = mutableListOf<Int>()
|
||||
for (j in 0..<n) {
|
||||
tmp.add(0)
|
||||
}
|
||||
numList.add(tmp)
|
||||
}
|
||||
}
|
||||
|
||||
/* Quadratic order (recursive implementation) */
|
||||
tailrec fun quadraticRecur(n: Int): Int {
|
||||
if (n <= 0)
|
||||
return 0
|
||||
// Array nums has length n, n-1, ..., 2, 1
|
||||
val nums = Array(n) { 0 }
|
||||
println("In recursion n = $n, nums length = ${nums.size}")
|
||||
return quadraticRecur(n - 1)
|
||||
}
|
||||
|
||||
/* Driver Code */
|
||||
fun buildTree(n: Int): TreeNode? {
|
||||
if (n == 0)
|
||||
return null
|
||||
val root = TreeNode(0)
|
||||
root.left = buildTree(n - 1)
|
||||
root.right = buildTree(n - 1)
|
||||
return root
|
||||
}
|
||||
|
||||
/* Driver Code */
|
||||
fun main() {
|
||||
val n = 5
|
||||
// Constant order
|
||||
constant(n)
|
||||
// Linear order
|
||||
linear(n)
|
||||
linearRecur(n)
|
||||
// Exponential order
|
||||
quadratic(n)
|
||||
quadraticRecur(n)
|
||||
// Exponential order
|
||||
val root = buildTree(n)
|
||||
printTree(root)
|
||||
}
|
||||
@@ -0,0 +1,168 @@
|
||||
/**
|
||||
* File: time_complexity.kt
|
||||
* Created Time: 2024-01-25
|
||||
* Author: curtishd (1023632660@qq.com)
|
||||
*/
|
||||
|
||||
package chapter_computational_complexity.time_complexity
|
||||
|
||||
/* Constant order */
|
||||
fun constant(n: Int): Int {
|
||||
var count = 0
|
||||
val size = 100000
|
||||
for (i in 0..<size)
|
||||
count++
|
||||
return count
|
||||
}
|
||||
|
||||
/* Linear order */
|
||||
fun linear(n: Int): Int {
|
||||
var count = 0
|
||||
for (i in 0..<n)
|
||||
count++
|
||||
return count
|
||||
}
|
||||
|
||||
/* Linear order (traversing array) */
|
||||
fun arrayTraversal(nums: IntArray): Int {
|
||||
var count = 0
|
||||
// Number of iterations is proportional to the array length
|
||||
for (num in nums) {
|
||||
count++
|
||||
}
|
||||
return count
|
||||
}
|
||||
|
||||
/* Exponential order */
|
||||
fun quadratic(n: Int): Int {
|
||||
var count = 0
|
||||
// Number of iterations is quadratically related to the data size n
|
||||
for (i in 0..<n) {
|
||||
for (j in 0..<n) {
|
||||
count++
|
||||
}
|
||||
}
|
||||
return count
|
||||
}
|
||||
|
||||
/* Quadratic order (bubble sort) */
|
||||
fun bubbleSort(nums: IntArray): Int {
|
||||
var count = 0 // Counter
|
||||
// Outer loop: unsorted range is [0, i]
|
||||
for (i in nums.size - 1 downTo 1) {
|
||||
// Inner loop: swap the largest element in the unsorted range [0, i] to the rightmost end of that range
|
||||
for (j in 0..<i) {
|
||||
if (nums[j] > nums[j + 1]) {
|
||||
// Swap nums[j] and nums[j + 1]
|
||||
val temp = nums[j]
|
||||
nums[j] = nums[j + 1]
|
||||
nums[j + 1] = temp
|
||||
count += 3 // Element swap includes 3 unit operations
|
||||
}
|
||||
}
|
||||
}
|
||||
return count
|
||||
}
|
||||
|
||||
/* Exponential order (loop implementation) */
|
||||
fun exponential(n: Int): Int {
|
||||
var count = 0
|
||||
var base = 1
|
||||
// Cells divide into two every round, forming sequence 1, 2, 4, 8, ..., 2^(n-1)
|
||||
for (i in 0..<n) {
|
||||
for (j in 0..<base) {
|
||||
count++
|
||||
}
|
||||
base *= 2
|
||||
}
|
||||
// count = 1 + 2 + 4 + 8 + .. + 2^(n-1) = 2^n - 1
|
||||
return count
|
||||
}
|
||||
|
||||
/* Exponential order (recursive implementation) */
|
||||
fun expRecur(n: Int): Int {
|
||||
if (n == 1) {
|
||||
return 1
|
||||
}
|
||||
return expRecur(n - 1) + expRecur(n - 1) + 1
|
||||
}
|
||||
|
||||
/* Logarithmic order (loop implementation) */
|
||||
fun logarithmic(n: Int): Int {
|
||||
var n1 = n
|
||||
var count = 0
|
||||
while (n1 > 1) {
|
||||
n1 /= 2
|
||||
count++
|
||||
}
|
||||
return count
|
||||
}
|
||||
|
||||
/* Logarithmic order (recursive implementation) */
|
||||
fun logRecur(n: Int): Int {
|
||||
if (n <= 1)
|
||||
return 0
|
||||
return logRecur(n / 2) + 1
|
||||
}
|
||||
|
||||
/* Linearithmic order */
|
||||
fun linearLogRecur(n: Int): Int {
|
||||
if (n <= 1)
|
||||
return 1
|
||||
var count = linearLogRecur(n / 2) + linearLogRecur(n / 2)
|
||||
for (i in 0..<n) {
|
||||
count++
|
||||
}
|
||||
return count
|
||||
}
|
||||
|
||||
/* Factorial order (recursive implementation) */
|
||||
fun factorialRecur(n: Int): Int {
|
||||
if (n == 0)
|
||||
return 1
|
||||
var count = 0
|
||||
// Split from 1 into n
|
||||
for (i in 0..<n) {
|
||||
count += factorialRecur(n - 1)
|
||||
}
|
||||
return count
|
||||
}
|
||||
|
||||
/* Driver Code */
|
||||
fun main() {
|
||||
// You can modify n to run and observe the trend of the number of operations for various complexities
|
||||
val n = 8
|
||||
println("Input data size n = $n")
|
||||
|
||||
var count = constant(n)
|
||||
println("Constant-time operations count = $count")
|
||||
|
||||
count = linear(n)
|
||||
println("Linear-time operations count = $count")
|
||||
count = arrayTraversal(IntArray(n))
|
||||
println("Linear-time (array traversal) operations count = $count")
|
||||
|
||||
count = quadratic(n)
|
||||
println("Quadratic-time operations count = $count")
|
||||
val nums = IntArray(n)
|
||||
for (i in 0..<n)
|
||||
nums[i] = n - i // [n,n-1,...,2,1]
|
||||
count = bubbleSort(nums)
|
||||
println("Quadratic-time (bubble sort) operations count = $count")
|
||||
|
||||
count = exponential(n)
|
||||
println("Exponential-time (iterative) operations count = $count")
|
||||
count = expRecur(n)
|
||||
println("Exponential-time (recursive) operations count = $count")
|
||||
|
||||
count = logarithmic(n)
|
||||
println("Logarithmic-time (iterative) operations count = $count")
|
||||
count = logRecur(n)
|
||||
println("Logarithmic-time (recursive) operations count = $count")
|
||||
|
||||
count = linearLogRecur(n)
|
||||
println("Linearithmic-time (recursive) operations count = $count")
|
||||
|
||||
count = factorialRecur(n)
|
||||
println("Factorial-time (recursive) operations count = $count")
|
||||
}
|
||||
@@ -0,0 +1,45 @@
|
||||
/**
|
||||
* File: worst_best_time_complexity.kt
|
||||
* Created Time: 2024-01-25
|
||||
* Author: curtishd (1023632660@qq.com)
|
||||
*/
|
||||
|
||||
package chapter_computational_complexity.worst_best_time_complexity
|
||||
|
||||
/* Generate an array with elements { 1, 2, ..., n }, order shuffled */
|
||||
fun randomNumbers(n: Int): Array<Int?> {
|
||||
val nums = IntArray(n)
|
||||
// Generate array nums = { 1, 2, 3, ..., n }
|
||||
for (i in 0..<n) {
|
||||
nums[i] = i + 1
|
||||
}
|
||||
// Randomly shuffle array elements
|
||||
nums.shuffle()
|
||||
val res = arrayOfNulls<Int>(n)
|
||||
for (i in 0..<n) {
|
||||
res[i] = nums[i]
|
||||
}
|
||||
return res
|
||||
}
|
||||
|
||||
/* Find the index of number 1 in array nums */
|
||||
fun findOne(nums: Array<Int?>): Int {
|
||||
for (i in nums.indices) {
|
||||
// When element 1 is at the head of the array, best time complexity O(1) is achieved
|
||||
// When element 1 is at the tail of the array, worst time complexity O(n) is achieved
|
||||
if (nums[i] == 1)
|
||||
return i
|
||||
}
|
||||
return -1
|
||||
}
|
||||
|
||||
/* Driver Code */
|
||||
fun main() {
|
||||
for (i in 0..9) {
|
||||
val n = 100
|
||||
val nums = randomNumbers(n)
|
||||
val index = findOne(nums)
|
||||
println("\nArray [ 1, 2, ..., n ] after shuffling = ${nums.contentToString()}")
|
||||
println("Index of number 1 is $index")
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user