C++ error link
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C语言OOP实现
union
union
在C/C++程序的编写中,当多个基本数据类型或复合数据结构要占用同一片内存时,我们要使用联合体;当多种类型,多个对象,多个事物只取其一时(我们姑且通俗地称其为“n 选1”),我们也可以使用联合体来发挥其长处。
vector4 用来表示向量和颜色
1 | struct vector4 |
1 | void test() { |
Codeforces Round.648
codeforces.1363F_Rotating Substrings
1363F Rotating Substrings
问题描述
You are given two strings s and t, each of length n and consisting of lowercase Latin alphabets. You want to make s equal to t.
You can perform the following operation on s any number of times to achieve it —
Choose any substring of s and rotate it clockwise once, that is, if the selected substring is s[l,l+1…r], then it becomes s[r,l,l+1…r−1]. All the remaining characters of s stay in their position.
For example, on rotating the substring [2,4] , string “abcde” becomes “adbce”.
A string a is a substring of a string b if a can be obtained from b by deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters from the end.
Find the minimum number of operations required to convert s to t, or determine that it’s impossible.
Input
The first line of the input contains a single integer t (1≤t≤2000) — the number of test cases. The description of the test cases follows.
The first line of each test case contains a single integer n (1≤n≤2000) — the length of the strings.