夏夜、

摘要： DFS枚举每个点开始的全部长度为6的数字串，插入到set里面。//#pragma comment(linker, "/STACK:1024000000,1024000000")#include#include#include#include#include#include#include#include#include#include#include#include#include#includeusing namespace std;typedef long long ll;typedef unsigned long long ull;typedef pair pii;# 阅读全文

摘要： 用next_permutation枚举全排列。//#pragma comment(linker, "/STACK:1024000000,1024000000")#include#include#include#include#include#include#include#include#include#include#include#include#include#includeusing namespace std;typedef long long ll;typedef unsigned long long ull;typedef pair pii;#define p 阅读全文

摘要： 不用说，想让两个数的差最小，那这个两个数的位数要最接近。不妨设a>b;如果n是奇数 a就是最小的(n/2+1)位数，b就是最大的n/2位数如果是偶数 枚举每一对相邻的数，大的作为a的第一位，小的作为b的第一位，然后就一样了。//#pragma comment(linker, "/STACK:1024000000,1024000000")#include#include#include#include#include#include#include#include#include#include#include#include#include#includeusing 阅读全文

摘要： 读懂题意就能写了，递归层数最多10，怎么写都能过。DFS：//#pragma comment(linker, "/STACK:1024000000,1024000000")#include#include#include#include#include#include#include#include#include#include#include#include#include#includeusing namespace std;typedef long long ll;typedef unsigned long long ull;typedef pair pii;#de 阅读全文