From d3e15a88563713444b0a6ef3a5d745bd30165396 Mon Sep 17 00:00:00 2001 From: RiverTwilight Date: Mon, 2 Jan 2023 20:52:15 +0800 Subject: [PATCH] lint: var to let --- .../time_complexity.js | 42 ++--- .../time_complexity.ts | 154 ++++++++++++++++++ 2 files changed, 175 insertions(+), 21 deletions(-) diff --git a/codes/javascript/chapter_computational_complexity/time_complexity.js b/codes/javascript/chapter_computational_complexity/time_complexity.js index b1a9eb7c5..d044f22f0 100644 --- a/codes/javascript/chapter_computational_complexity/time_complexity.js +++ b/codes/javascript/chapter_computational_complexity/time_complexity.js @@ -6,24 +6,24 @@ /* 常数阶 */ function constant(n) { - var count = 0; + let count = 0; const size = 100000; - for (var i = 0; i < size; i++) count++; + for (let i = 0; i < size; i++) count++; return count; } /* 线性阶 */ function linear(n) { - var count = 0; - for (var i = 0; i < n; i++) count++; + let count = 0; + for (let i = 0; i < n; i++) count++; return count; } /* 线性阶（遍历数组） */ function arrayTraversal(nums) { - var count = 0; + let count = 0; // 循环次数与数组长度成正比 - for (var i = 0; i < nums.length; i++) { + for (let i = 0; i < nums.length; i++) { count++; } return count; @@ -31,9 +31,9 @@ function arrayTraversal(nums) { /* 平方阶 */ function quadratic(n) { - var count = 0; + let count = 0; // 循环次数与数组长度成平方关系 - for (var i = 0; i < n; i++) { + for (let i = 0; i < n; i++) { for (let j = 0; j < n; j++) { count++; } @@ -43,9 +43,9 @@ function quadratic(n) { /* 平方阶（冒泡排序） */ function bubbleSort(nums) { - var count = 0; // 计数器 + let count = 0; // 计数器 // 外循环：待排序元素数量为 n-1, n-2, ..., 1 - for (var i = nums.length - 1; i > 0; i--) { + for (let i = nums.length - 1; i > 0; i--) { // 内循环：冒泡操作 for (let j = 0; j < i; j++) { if (nums[j] > nums[j + 1]) { @@ -62,10 +62,10 @@ function bubbleSort(nums) { /* 指数阶（循环实现） */ function exponential(n) { - var count = 0, + let count = 0, base = 1; // cell 每轮一分为二，形成数列 1, 2, 4, 8, ..., 2^(n-1) - for (var i = 0; i < n; i++) { + for (let i = 0; i < n; i++) { for (let j = 0; j < base; j++) { count++; } @@ -83,7 +83,7 @@ function expRecur(n) { /* 对数阶（循环实现） */ function logarithmic(n) { - var count = 0; + let count = 0; while (n > 1) { n = n / 2; count++; @@ -100,8 +100,8 @@ function logRecur(n) { /* 线性对数阶 */ function linearLogRecur(n) { if (n <= 1) return 1; - var count = linearLogRecur(n / 2) + linearLogRecur(n / 2); - for (var i = 0; i < n; i++) { + let count = linearLogRecur(n / 2) + linearLogRecur(n / 2); + for (let i = 0; i < n; i++) { count++; } return count; @@ -110,18 +110,18 @@ function linearLogRecur(n) { /* 阶乘阶（递归实现） */ function factorialRecur(n) { if (n == 0) return 1; - var count = 0; + let count = 0; // 从 1 个分裂出 n 个 - for (var i = 0; i < n; i++) { + for (let i = 0; i < n; i++) { count += factorialRecur(n - 1); } return count; } -var n = 8; +let n = 8; console.log("输入数据大小 n = " + n); -var count = constant(n); +let count = constant(n); console.log("常数阶的计算操作数量 = " + count); count = linear(n); @@ -131,8 +131,8 @@ console.log("线性阶（遍历数组）的计算操作数量 = " + count); count = quadratic(n); console.log("平方阶的计算操作数量 = " + count); -var nums = new Array(n); -for (var i = 0; i < n; i++) nums[i] = n - i; // [n,n-1,...,2,1] +let nums = new Array(n); +for (let i = 0; i < n; i++) nums[i] = n - i; // [n,n-1,...,2,1] count = bubbleSort(nums); console.log("平方阶（冒泡排序）的计算操作数量 = " + count); diff --git a/codes/typescript/chapter_computational_complexity/time_complexity.ts b/codes/typescript/chapter_computational_complexity/time_complexity.ts index 9c877602f..f722a1117 100644 --- a/codes/typescript/chapter_computational_complexity/time_complexity.ts +++ b/codes/typescript/chapter_computational_complexity/time_complexity.ts @@ -3,3 +3,157 @@ * Created Time: 2023-01-02 * Author: RiverTwilight (contact@rene.wang) */ + +/** + * File: time_complexity.js + * Created Time: 2023-01-02 + * Author: RiverTwilight (contact@rene.wang) + */ + +/* 常数阶 */ +function constant(n: number): number { + let count = 0; + const size = 100000; + for (let i = 0; i < size; i++) count++; + return count; +} + +/* 线性阶 */ +function linear(n: number): number { + let count = 0; + for (let i = 0; i < n; i++) count++; + return count; +} + +/* 线性阶（遍历数组） */ +function arrayTraversal(nums) { + let count = 0; + // 循环次数与数组长度成正比 + for (let i = 0; i < nums.length; i++) { + count++; + } + return count; +} + +/* 平方阶 */ +function quadratic(n: number): number { + let count = 0; + // 循环次数与数组长度成平方关系 + for (let i = 0; i < n; i++) { + for (let j = 0; j < n; j++) { + count++; + } + } + return count; +} + +/* 平方阶（冒泡排序） */ +function bubbleSort(nums: number[]): number { + let count = 0; // 计数器 + // 外循环：待排序元素数量为 n-1, n-2, ..., 1 + for (let i = nums.length - 1; i > 0; i--) { + // 内循环：冒泡操作 + for (let j = 0; j < i; j++) { + if (nums[j] > nums[j + 1]) { + // 交换 nums[j] 与 nums[j + 1] + let tmp = nums[j]; + nums[j] = nums[j + 1]; + nums[j + 1] = tmp; + count += 3; // 元素交换包含 3 个单元操作 + } + } + } + return count; +} + +/* 指数阶（循环实现） */ +function exponential(n: number): number { + let count = 0, + base = 1; + // cell 每轮一分为二，形成数列 1, 2, 4, 8, ..., 2^(n-1) + for (let i = 0; i < n; i++) { + for (let j = 0; j < base; j++) { + count++; + } + base *= 2; + } + // count = 1 + 2 + 4 + 8 + .. + 2^(n-1) = 2^n - 1 + return count; +} + +/* 指数阶（递归实现） */ +function expRecur(n: number): number { + if (n == 1) return 1; + return expRecur(n - 1) + expRecur(n - 1) + 1; +} + +/* 对数阶（循环实现） */ +function logarithmic(n: number): number { + let count = 0; + while (n > 1) { + n = n / 2; + count++; + } + return count; +} + +/* 对数阶（递归实现） */ +function logRecur(n: number): number { + if (n <= 1) return 0; + return logRecur(n / 2) + 1; +} + +/* 线性对数阶 */ +function linearLogRecur(n: number): number { + if (n <= 1) return 1; + let count = linearLogRecur(n / 2) + linearLogRecur(n / 2); + for (let i = 0; i < n; i++) { + count++; + } + return count; +} + +/* 阶乘阶（递归实现） */ +function factorialRecur(n: number): number { + if (n == 0) return 1; + let count = 0; + // 从 1 个分裂出 n 个 + for (let i = 0; i < n; i++) { + count += factorialRecur(n - 1); + } + return count; +} + +var n: number = 8; +console.log("输入数据大小 n = " + n); + +let count = constant(n); +console.log("常数阶的计算操作数量 = " + count); + +count = linear(n); +console.log("线性阶的计算操作数量 = " + count); +count = arrayTraversal(new Array(n)); +console.log("线性阶（遍历数组）的计算操作数量 = " + count); + +count = quadratic(n); +console.log("平方阶的计算操作数量 = " + count); +var nums = new Array(n); +for (let i = 0; i < n; i++) nums[i] = n - i; // [n,n-1,...,2,1] +count = bubbleSort(nums); +console.log("平方阶（冒泡排序）的计算操作数量 = " + count); + +count = exponential(n); +console.log("指数阶（循环实现）的计算操作数量 = " + count); +count = expRecur(n); +console.log("指数阶（递归实现）的计算操作数量 = " + count); + +count = logarithmic(n); +console.log("对数阶（循环实现）的计算操作数量 = " + count); +count = logRecur(n); +console.log("对数阶（递归实现）的计算操作数量 = " + count); + +count = linearLogRecur(n); +console.log("线性对数阶（递归实现）的计算操作数量 = " + count); + +count = factorialRecur(n); +console.log("阶乘阶（递归实现）的计算操作数量 = " + count);