树的同构 poj 1635

链接

题意

解析

代码

#include <cstdio>
#include <cstring>
#include <vector>
#include <algorithm>
#include <iostream>
#include <map>
#include <queue>
using namespace std;
const int maxn = 3000+10;
typedef long long LL;
vector<int>G1[maxn];
vector<int>G2[maxn];
int p1[maxn], p2[maxn];
struct hash{
int length;
LL value;
hash():length(0), value(0){}
hash(char c):length(1), value(c){}
hash(int l, LL v):length(l), value(v){}
bool operator < (const hash &a) const
{
return value<a.value;
}
};
const LL magic = 321;
LL pow(LL a, int b){
LL res = 1;
while (b) {
if (b & 1)
res *= a;
a *= a;
b>>=1;
}
return res;
}

hash operator + (const hash &a, const hash &b)
{
return hash(a.length+b.length, a.value*pow(magic, b.length)+b.value);
}

void operator += (hash &a, const hash &b){
a = a+b;
}

vector<hash>child[maxn];
hash dfs(int pre, int cur, vector<int>G[maxn]) {
hash ret;
child[cur].clear();
for (int i=0; i<G[cur].size(); i++) {
if (G[cur][i] == pre)
continue;
child[cur].push_back(dfs(cur, G[cur][i], G));
}
sort(child[cur].begin(), child[cur].end());
for (int i=0; i<child[cur].size(); i++)
ret += child[cur][i];
ret = '(' + ret + ')';
return ret;
}

LL gethash(int root, vector<int>m[maxn]) {
return dfs(-1, root, m).value;
}
int main() {
int T;
scanf("%d", &T);
while (T--) {
char s[maxn];
scanf("%s", s);
int slen = strlen(s);
int t=0;
int now = 0;
for (int i=0; i<slen; i++)
G1[i].clear(), G2[i].clear();

for (int i=0; i<slen; i++) {
if (s[i] == '1')
now = p1[now];
else
{
t++;
G1[now].push_back(t);
p1[t] = now;
now = t;
}
}
char p[maxn];
scanf("%s", p);
int plen = strlen(p);
t = 0;
now = 0;
for (int i=0; i<plen; i++) {
if (p[i] == '1')
now = p2[now];
else {
t++;
G2[now].push_back(t);
p2[t] = now;
now = t;
}
}
if (slen != plen) {
puts("differrent");
continue;
}
LL tree1 = gethash(0, G1);
LL tree2 = gethash(0, G2);
if (tree1 == tree2)
puts("same");
else
puts("different");
}
return 0;
}