IDrandom的专栏

TensorFlow2.x 学习笔记(八)过拟合

IDrandom — Wed, 13 May 2020 04:36:46 +0800

过拟合与欠拟合 Model capacity 当模型的复杂度增强时，模型的表达性也随之增强，以多项式为例 y=β0+β1x+β2x2+...+βnxn+ϵy = \beta_0 + \beta_1x + \beta_2x^2 + ... + \beta_nx^n + \epsilony=β0+β1x+β2x2+...+βnxn+ϵ 随着阶数的增加，可表示的模型也就越多，模型的表示能力也就越强。 Underfitting model capacity < ground truth train

TensorFlow2.x 学习笔记(七)Keras高层接口

IDrandom — Tue, 14 Apr 2020 04:07:38 +0800

Keras高层接口这里所指的均为tf.keras Keras高层API metrics acc_meter = metrics.Accuracy() loss_meter = metrics.Mean() update_state loss_meter.update_state(loss) acc_meter.udate_state(y, pred) result().numpy() pri...

TensorFlow2.x 学习笔记(六)随机梯度下降以及数据可视化

IDrandom — Thu, 09 Apr 2020 03:18:29 +0800

梯度下降简介梯度梯度是一个向量，表示某一函数在该点处的方向导数沿着该方向取得最大值。 gradf(x,y)=∇f(x,y)=(∂f∂x,∂f∂y)=∂f∂xi+∂f∂xjgradf(x,y) = \nabla{f(x,y)} = (\frac{\partial f}{\partial x},\frac{\partial f}{\partial y}) = \frac{\partial f}{...

TensorFlow2.x 学习笔记(五)神经网络与全连接层

IDrandom — Thu, 19 Mar 2020 03:59:58 +0800

数据加载 keras.datasets boston housing Boston housing price regression dataset mnist/fashion mnist MNIST/Fashion-MNIST dataset MNIST (x, y), (x_test, y_test) = keras.datasets.mnist.load_data() x.shape...

[LeetCode 1351~1354][周赛]周赛176题解

IDrandom — Thu, 05 Mar 2020 03:36:03 +0800

这场周赛还是有点意思的，没有那么水，大概hard有cf div2 D的感觉 1351. 统计有序矩阵中的负数题目链接第一种：二分 static const auto io_speed_up = [](){ ios::sync_with_stdio(false); cin.tie(0); return 0; }(); class Solution { public: ...

[LeetCode 1356~1359][周赛]双周赛20题解

IDrandom — Wed, 04 Mar 2020 01:46:47 +0800

根据数字二进制下 1 的数目排序题目链接 static const auto io_speed_up = [](){ ios::sync_with_stdio(false); cin.tie(0); return 0; }(); class Solution { public: int cnt[10010]; vector sor...

[LeetCode 1360~1363][周赛]周赛177题解

IDrandom — Mon, 02 Mar 2020 17:50:23 +0800

1360.日期之间隔几天题目链接 static const auto io_speed_up = [](){ ios::sync_with_stdio(false); cin.tie(0); return 0; }(); class Solution { public: int nleap[13]={0, 31, 28, 31, 30, 31, 30, 31, 3...

[LeetCode 1365~1368][周赛]周赛178题解

IDrandom — Sun, 01 Mar 2020 14:38:16 +0800

5344.有多少小于当前数字的数字题目链接 static const auto io_speed_up = [](){ ios::sync_with_stdio(false); cin.tie(0); return 0; }(); class Solution { public: vector smallerNumbersThanCurren...

TensorFlow2.x 学习笔记(三)基础操作

IDrandom — Sun, 01 Mar 2020 03:49:17 +0800

数据类型 python Data Container list ：消耗大 np.array ：无GPU tf.tensor TF is a computing lib Creat tf.constant(1) # int tf.constant(1.) # float32 tf.constant(2.2, dtype=tf.int32) # error tf.constant(2., dtyp...

TensorFlow2.x 学习笔记(二)回归问题&分类问题

IDrandom — Sun, 01 Mar 2020 03:48:54 +0800

fθ:x→yf_{\theta}: x\rightarrow yfθ:x→y yyy通常可以分为两类：离散或连续连续时为回归问题 linear regression loss function gradient descent loss surface convex Optimization linear regression linear Regression logistic Regr...

TensorFlow2.x 学习笔记(四)高级操作

IDrandom — Sun, 01 Mar 2020 03:47:37 +0800

合并与分割 Merge and split tf.concat [class1-4, students, scores] [class5-6, students, scores] a = tf.ones([4,35,8]) b = tf.ones([2,35,8]) c = tf.concat([a,b], axis=0) c.shape a = tf.ones([4,32,8]) b =...

[LeetCode 404, 405][简单]左叶子之和/数字转换为十六进制数

IDrandom — Sat, 29 Feb 2020 16:06:32 +0800

404.左叶子之和题目链接 static const auto io_speed_up =[](){ ios::sync_with_stdio(false); cin.tie(0); cout.tie(0); return 0; }(); class Solution { public: int sumOfLeftLeaves(TreeNode* root...

[LeetCode 392,401][简单]判断子序列/二进制手表

IDrandom — Fri, 28 Feb 2020 16:01:35 +0800

392.判断子序列题目链接 static const auto io_speed_up = [](){ ios::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); return NULL; }(); class Solution { public: bool isSubsequence(strin...

[LeetCode 387,389][简单]字符串中的第一个唯一字符/找不同

IDrandom — Thu, 27 Feb 2020 16:25:02 +0800

387.字符串中的第一个唯一字符题目链接 static const auto io_speed_up = [](){ ios::sync_with_stdio(false); cin.tie(0); return 0; }(); class Solution { public: int firstUniqChar(string s) { int f...

[LeetCode 374,383][简单]猜数字大小/赎金信

IDrandom — Wed, 26 Feb 2020 17:24:27 +0800

374.猜数字大小题目链接 static const auto io_speed_up = []() { ios::sync_with_stdio(0); cin.tie(0); return 0; }(); int guess(int num); class Solution { public: typedef long long LL; int gu...

[LeetCode 367,371][简单]有效的完全平方数/两整数之和

IDrandom — Tue, 25 Feb 2020 15:13:47 +0800

367.有效的完全平方数题目链接 static const auto io_speed_up = []() { ios::sync_with_stdio(0); cin.tie(0); return 0; }(); class Solution { public: bool isPerfectSquare(int num) { double ans...

[LeetCode 349,350][简单]两个数组的交集/两个数组的交集 II

IDrandom — Mon, 24 Feb 2020 15:46:37 +0800

349.两个数组的交集题目链接 static const auto io_speed_up = []() { ios::sync_with_stdio(0); cin.tie(0); return 0; }(); class Solution { public: vector intersection(vector&am...

[LeetCode 344,345][简单]反转字符串/反转字符串中的元音字母

IDrandom — Sun, 23 Feb 2020 16:59:24 +0800

344.反转字符串题目链接 static const auto io_speed_up = []() { ios::sync_with_stdio(false); cin.tie(0); return 0; }(); class Solution { public: void reverseString(vector& s) {...

[LeetCode 326,342][简单]3的幂/4的幂

IDrandom — Sun, 23 Feb 2020 16:32:21 +0800

326.3的幂题目链接比较好想的是取对数法。 class Solution { public: double eps = 1e-11; bool isPowerOfThree(int n) { if(n<=0)return 0; double pw = log2(n) / log2(3.0); return fabs(rou...

[LeetCode 299,303][简单]猜数字游戏/区域和检索 - 数组不可变

IDrandom — Sat, 22 Feb 2020 22:39:14 +0800

299.猜数字游戏题目链接 class Solution { public: string getHint(string secret, string guess) { ios::sync_with_stdio(0); cin.tie(0); int a[10]={0},b[10]={0}; int acnt=0,bcnt=...