Some major cities have subway systems in the form of a tree, i.e. between any pair of stations, there is one and only one way of going by subway. Moreover, most of these cities have a unique central station. Imagine you are a tourist in one of these…
#include <iostream> using namespace std; struct Tree { int data; Tree *lchild; Tree *rchild; }tree; Tree *Create(int a1[],int b1[],int n) { int k; ) return NULL; ]; Tree *bt=(Tree *)malloc(sizeof(Tree)); bt->data=root; ;k<n;k++) { if(b1[k]==ro…
Given two strings s and t, determine if they are isomorphic. Two strings are isomorphic if the characters in s can be replaced to get t. All occurrences of a character must be replaced with another character while preserving the order of characters.…
枚举$T_1$的树根,然后DP,设$f[i][j]$表示$T_1$的子树$i$是否存在包括i的连通子树与$T_2$的子树$j$同构. 若$j$是叶子,那么显然可以. 若$deg_i<deg_j$,那么显然不可以. 否则将$i$与$j$所有互相同构的儿子之间连边,二分图匹配判断是否存在完美匹配即可. #include<cstdio> #include<algorithm> const int N=105; int T,C,n,m,o,i,j,k,x,y; int g[N],v[…
