POJ1635:Subway tree systems

链接：http://poj.org/problem?id=1635

填坑树同构

题目给出的是除根外的括号序列表示。

其实只要跟你说hash大家都能写得出来……

hash函数取个效果别太差的就行了吧

#include<vector>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define MN 3111
using namespace std;

int read_p,read_ca;
inline int read(){
    read_p=0;read_ca=getchar();
    while(read_ca<'0'||read_ca>'9') read_ca=getchar();
    while(read_ca>='0'&&read_ca<='9') read_p=read_p*10+read_ca-48,read_ca=getchar();
    return read_p;
}
const int HA=1e4+7;
int T,n,m,ha[MN],a,b;
char s[MN],c[MN];
int dfs(char s[],int &p){
    int mmh=ha[0];
    vector <int> hash;
    for (p++;s[p]!='1';) hash.push_back(dfs(s,p));
    p++;
    sort(hash.begin(),hash.end());
    for (int i=0;i<hash.size();i++)
    mmh=(mmh^hash[i])*ha[i+1]%HA;
    return mmh;
}
int main(){
    T=read();
    for (int i=0;i<MN;i++) ha[i]=rand()%HA;
    while (T--){
        scanf("%s%s",s+1,c+1);a=b=0;
        s[0]=c[0]='0';s[strlen(s+1)+1]='1';c[strlen(c+1)+1]='1';
        puts(dfs(s,a)==dfs(c,b)?"same":"different");
    }
}