最近在处理一个小功能,每个元素可以有多个图片,每个图片的name表示了它是背景图还是海报图, 需要对每个元素的图片name做一个唯一性验证,一个元素不能添加两个海报图, 需要使用的是validates_uniqueness_of http://api.rubyonrails.org/classes/ActiveRecord/Validations/ClassMethods.html#method-i-validates_uniqueness_of Validates whether the va…

使用PowerDesigner生成数据库脚本时报 Constraint name uniqueness 错误: 双击每行错误,发现外键引用的名字有重复的: 惯性去网上找解决办法,找到的主要是两个方法: 1.使用Automatic Correction 右键错误行,菜单中选择Automatic Correction,自动更正错误. 这样Constraint name 就会自动编号处理. 2.手动修改Constraint name 在外键引用编辑页面,点击Constraint name最右面的那个头…

Introduction Among simulation engineers, it is well accepted that the solution of a PDE can be envisioned as the following three general steps (actually, this was also my premature understanding during the early era of my study on numerical simulatio…

使用PowerDesigner生成数据库脚本时报 Constraint name uniqueness 错误: 双击每行错误,发现外键引用的名字有重复的: 惯性去网上找解决办法,找到的主要是两个方法: 1.使用Automatic Correction 右键错误行,菜单中选择Automatic Correction,自动更正错误. 这样Constraint name 就会自动编号处理. 2.手动修改Constraint name 在外键引用编辑页面,点击Constraint name最右面的那个头…

选择"Tools -> Model Options"后 "Allow reuse"复选框,建议把这个钩也去掉 Tool->check model...去掉Entity Attribute下Entity Attribute name uniqueness 和 Entity Attribute code uniqueness…

题意 Split a unique array into two almost unique arrays. unique arrays指数组各个数均不相同,almost unique arrays指可以删掉数后再判断. 思路 略神的数学构造题... 官方题解: An equivalent definition for almost unique, is arrays with at least ⌊ 2n / 3⌋ different elements. The idea is to split…

C. Splitting the Uniqueness time limit per test:1 second memory limit per test:256 megabytes input:standard input output:standard output Polar bears like unique arrays — that is, arrays without repeated elements. You have got a unique array s with le…

B. Uniqueness time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given an array a1,a2,…,ana1,a2,…,an. You can remove at most one subsegment from it. The remaining elements should be p…

B. Uniqueness 给定一个序列,要求删除一段连续子段,满足删掉子段后每个元素唯一 求最小子段长度 枚举起点,二分子段长度 记得先sort 再unique #include<bits/stdc++.h> using namespace std; #define int long long #define si signed #define endl '\n' #define sc(x) scanf("%I64d",&x); #define read(A) f…

B. Uniqueness time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output You are given an array a1,a2,…,ana1,a2,…,an. You can remove at most one subsegment from it. The remaining elements should be p…