From 4eb950d5f78d893bd9a649e0ebec44d023f44376 Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Wed, 26 May 2021 16:25:47 +0800 Subject: [PATCH 1/5] =?UTF-8?q?=E6=B7=BB=E5=8A=A0232.=E7=94=A8=E6=A0=88?= =?UTF-8?q?=E5=AE=9E=E7=8E=B0=E9=98=9F=E5=88=97JavaScript=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0232.用栈实现队列.md | 55 +++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) diff --git a/problems/0232.用栈实现队列.md b/problems/0232.用栈实现队列.md index 7c91a0dd..10314a08 100644 --- a/problems/0232.用栈实现队列.md +++ b/problems/0232.用栈实现队列.md @@ -353,6 +353,61 @@ func (this *MyQueue) Empty() bool { */ ``` + javaScript: + + ```js + // 使用两个数组的栈方法（push, pop） 实现队列 + /** + * Initialize your data structure here. + */ +var MyQueue = function() { + this.stack1 = []; + this.stack2 = []; +}; + +/** + * Push element x to the back of queue. + * @param {number} x + * @return {void} + */ +MyQueue.prototype.push = function(x) { + this.stack1.push(x); +}; + +/** + * Removes the element from in front of queue and returns that element. + * @return {number} + */ +MyQueue.prototype.pop = function() { + const size = this.stack2.length; + if(size) { + return this.stack2.pop(); + } + while(this.stack1.length) { + this.stack2.push(this.stack1.pop()); + } + return this.stack2.pop(); +}; + +/** + * Get the front element. + * @return {number} + */ +MyQueue.prototype.peek = function() { + const x = this.pop(); + this.stack2.push(x); + return x; +}; + +/** + * Returns whether the queue is empty. + * @return {boolean} + */ +MyQueue.prototype.empty = function() { + return !this.stack1.length && !this.stack2.length +}; + ``` + From 0eb61a58b38ef5d49ff94177ef69c7cfbca5ac4f Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Wed, 26 May 2021 16:52:44 +0800 Subject: [PATCH 2/5] =?UTF-8?q?=E6=B7=BB=E5=8A=A0225.=20=E7=94=A8=E9=98=9F?= =?UTF-8?q?=E5=88=97=E5=AE=9E=E7=8E=B0=E6=A0=88JavaScript=E7=89=88?= =?UTF-8?q?=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0225.用队列实现栈.md | 107 ++++++++++++++++++++++++++++ 1 file changed, 107 insertions(+) diff --git a/problems/0225.用队列实现栈.md b/problems/0225.用队列实现栈.md index e045229f..055c2e3d 100644 --- a/problems/0225.用队列实现栈.md +++ b/problems/0225.用队列实现栈.md @@ -357,8 +357,115 @@ class MyStack: Go： +javaScript: +使用数组（push, shift）模拟队列 +```js + +// 使用两个队列实现 +/** + * Initialize your data structure here. + */ +var MyStack = function() { + this.queue1 = []; + this.queue2 = []; +}; + +/** + * Push element x onto stack. + * @param {number} x + * @return {void} + */ +MyStack.prototype.push = function(x) { + this.queue1.push(x); +}; + +/** + * Removes the element on top of the stack and returns that element. + * @return {number} + */ +MyStack.prototype.pop = function() { + // 减少两个队列交换的次数， 只有当queue1为空时，交换两个队列 + if(!this.queue1.length) { + [this.queue1, this.queue2] = [this.queue2, this.queue1]; + } + while(this.queue1.length > 1) { + this.queue2.push(this.queue1.shift()); + } + return this.queue1.shift(); +}; + +/** + * Get the top element. + * @return {number} + */ +MyStack.prototype.top = function() { + const x = this.pop(); + this.queue1.push(x); + return x; +}; + +/** + * Returns whether the stack is empty. + * @return {boolean} + */ +MyStack.prototype.empty = function() { + return !this.queue1.length && !this.queue2.length; +}; + +``` + +```js + +// 使用一个队列实现 +/** + * Initialize your data structure here. + */ +var MyStack = function() { + this.queue = []; +}; + +/** + * Push element x onto stack. + * @param {number} x + * @return {void} + */ +MyStack.prototype.push = function(x) { + this.queue.push(x); +}; + +/** + * Removes the element on top of the stack and returns that element. + * @return {number} + */ +MyStack.prototype.pop = function() { + let size = this.queue.length; + while(size-- > 1) { + this.queue.push(this.queue.shift()); + } + return this.queue.shift(); +}; + +/** + * Get the top element. + * @return {number} + */ +MyStack.prototype.top = function() { + const x = this.pop(); + this.queue.push(x); + return x; +}; + +/** + * Returns whether the stack is empty. + * @return {boolean} + */ +MyStack.prototype.empty = function() { + return !this.queue.length; +}; + +``` ----------------------- * 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw) From 64b9363cd5079ba783461c54ad0a7a216b8f8512 Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Wed, 26 May 2021 17:01:03 +0800 Subject: [PATCH 3/5] =?UTF-8?q?=E6=B7=BB=E5=8A=A020.=20=E6=9C=89=E6=95=88?= =?UTF-8?q?=E7=9A=84=E6=8B=AC=E5=8F=B7JavaScript=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0020.有效的括号.md | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/problems/0020.有效的括号.md b/problems/0020.有效的括号.md index 315ff384..dae84354 100644 --- a/problems/0020.有效的括号.md +++ b/problems/0020.有效的括号.md @@ -271,6 +271,23 @@ var isValid = function (s) { } return stack.length === 0; }; +// 简化版本 +var isValid = function(s) { + const stack = [], + map = { + "(":")", + "{":"}", + "[":"]" + }; + for(const x of s) { + if(x in map) { + stack.push(x); + continue; + }; + if(map[stack.pop()] !== x) return false; + } + return !stack.length; +}; ``` From 0bb42237a2ec7336946c5386463a56fa56311872 Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Wed, 26 May 2021 17:16:01 +0800 Subject: [PATCH 4/5] =?UTF-8?q?=E6=B7=BB=E5=8A=A01047.=20=E5=88=A0?= =?UTF-8?q?=E9=99=A4=E5=AD=97=E7=AC=A6=E4=B8=B2=E4=B8=AD=E7=9A=84=E6=89=80?= =?UTF-8?q?=E6=9C=89=E7=9B=B8=E9=82=BB=E9=87=8D=E5=A4=8D=E9=A1=B9javaScrip?= =?UTF-8?q?t=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ...除字符串中的所有相邻重复项.md | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/problems/1047.删除字符串中的所有相邻重复项.md b/problems/1047.删除字符串中的所有相邻重复项.md index 8b761be7..9ca08c96 100644 --- a/problems/1047.删除字符串中的所有相邻重复项.md +++ b/problems/1047.删除字符串中的所有相邻重复项.md @@ -186,6 +186,24 @@ class Solution: Go： +javaScript: + +```js +/** + * @param {string} s + * @return {string} + */ +var removeDuplicates = function(s) { + const stack = []; + for(const x of s) { + let c = null; + if(stack.length && x === (c = stack.pop())) continue; + c && stack.push(c); + stack.push(x); + } + return stack.join(""); +}; +``` From 07e8abeccb423bf5501da54b6fd9dc89aaa703ee Mon Sep 17 00:00:00 2001 From: "qingyi.liu" Date: Wed, 26 May 2021 17:49:06 +0800 Subject: [PATCH 5/5] =?UTF-8?q?=E6=B7=BB=E5=8A=A0150.=20=E9=80=86=E6=B3=A2?= =?UTF-8?q?=E5=85=B0=E8=A1=A8=E8=BE=BE=E5=BC=8F=E6=B1=82=E5=80=BCjavaScrip?= =?UTF-8?q?t=E7=89=88=E6=9C=AC?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- problems/0150.逆波兰表达式求值.md | 26 +++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/problems/0150.逆波兰表达式求值.md b/problems/0150.逆波兰表达式求值.md index 618a6830..e38bc1a3 100644 --- a/problems/0150.逆波兰表达式求值.md +++ b/problems/0150.逆波兰表达式求值.md @@ -197,6 +197,32 @@ func evalRPN(tokens []string) int { } ``` +javaScript: + +```js + +/** + * @param {string[]} tokens + * @return {number} + */ +var evalRPN = function(tokens) { + const s = new Map([ + ["+", (a, b) => a * 1 + b * 1], + ["-", (a, b) => b - a], + ["*", (a, b) => b * a], + ["/", (a, b) => (b / a) | 0] + ]); + const stack = []; + for (const i of tokens) { + if(!s.has(i)) { + stack.push(i); + continue; + } + stack.push(s.get(i)(stack.pop(),stack.pop())) + } + return stack.pop(); +}; +``` -----------------------