C++-POJ3349-Snowflake Snow Snowflakes[STL][set][hash未写]

#include <set>
#include <map>
#include <cmath>
#include <queue>
#include <vector>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
struct node{
    int a,b,c,d,e,f,hash;
    node(int a,int b,int c,int d,int e,int f):a(a),b(b),c(c),d(d),e(e),f(f){}
    bool operator<(const node&x)const{
        if(a==x.a&&b==x.b&&c==x.c&&d==x.d&&e==x.e)return f<x.f;
        if(a==x.a&&b==x.b&&c==x.c&&d==x.d)return e<x.e;
        if(a==x.a&&b==x.b&&c==x.c)return d<x.d;
        if(a==x.a&&b==x.b)return c<x.c;
        if(a==x.a)return b<x.b;
        return a<x.a;
    }
};
set<node>s;
int n,l[6];

int main(){
    scanf("%d",&n);
    for(int i=1;i<=n;i++){
        scanf("%d%d%d%d%d%d",&l[0],&l[1],&l[2],&l[3],&l[4],&l[5]),sort(l,l+6);
        node snow=node(l[0],l[1],l[2],l[3],l[4],l[5]);
        if(s.find(snow)!=s.end()){puts("Twin snowflakes found.");return 0;}
        s.insert(snow);
    }
    puts("No two snowflakes are alike.");
    return 0;
}