CodeForces - 724G：Xor-matic Number of the Graph

1 #include<cstdio>
2 #include<cstdlib>
3 #include<algorithm>
4 #include<cstring>
5 #include<vector>
6 #define MOD 1000000007
7 #define MAXN 100000+10
8 #define ll long long
9 #define pb push_back
10 #define ft first
11 #define sc second
12 #define mp make_pair
13 #define pil pair<int,ll>
14 using namespace std;
15 int n,m;
16 vector<pil> G[MAXN];
17 ll d[MAXN];
18 int pw[MAXN];
19 vector<ll> vs;
20 vector<int> node;
21 void dfs(int x,ll c){
22     d[x]=c;node.pb(x);
23     for(int i=0;i<G[x].size();i++){
24         pil& t=G[x][i];
25         if(-1!=d[t.ft]){vs.pb(d[x]^d[t.ft]^t.sc);}
26         else{dfs(t.ft,c^t.sc);}
27     }
28 }
29 ll a[65];
30 ll ans;
31 ll solve(){
32     memset(a,0,sizeof(a));
33     int cnt=0;ll ret=0;
34     for(int i=0;i<vs.size();i++){
35         ll v=vs[i];
36         if(!v)continue;
37         for(int j=63;j>=0;j--){
38             if((v>>j)&1){
39                 if(!a[j]){
40                     cnt++;
41                     a[j]=v;
42                     break;
43                 }
44                 else{
45                     v^=a[j];
46                 }
47             }
48         }
49     }
50     for(int k=0;k<=63;k++){
51         int t[2]={0};
52         for(int i=0;i<node.size();i++){
53             t[(d[node[i]]>>k)&1]++;
54         }
55         bool flag=0;
56         for(int i=0;i<=63;i++){
57             if((a[i]>>k)&1){
58                 flag=1;break;
59             }
60         }
61         ll tmp=0;
62         if(!flag){
63             tmp+=(1LL*t[0]*t[1]%MOD*pw[cnt]%MOD);
64             tmp%=MOD;
65             tmp*=pw[k];
66             tmp%=MOD;
67         }
68         else{
69             tmp+=(1LL*t[0]*(t[0]-1))/2+(1LL*t[1]*(t[1]-1))/2+(1LL*t[0]*t[1]%MOD);
70             tmp%=MOD;
71             if(cnt)tmp*=pw[cnt-1],tmp%=MOD;
72             tmp*=pw[k];
73             tmp%=MOD;
74         }
75         ret+=tmp;
76         ret%=MOD;
77     }
78     return ret;
79 }
80 int main()
81 {
82 //    freopen("data.in","r",stdin);
83     pw[0]=1;
84     for(int i=1;i<=100;i++){
85         pw[i]=pw[i-1]*2%MOD;
86     }
87     scanf("%d%d",&n,&m);
88     int x,y;ll w;
89     for(int i=1;i<=m;i++){
90         scanf("%d%d%lld",&x,&y,&w);
91         G[x].pb(mp(y,w));G[y].pb(mp(x,w));
92     }
93     memset(d,-1,sizeof(d));
94     for(int i=1;i<=n;i++){
95         if(-1==d[i]){
96             vs.clear(),node.clear();
97             dfs(i,0);
98             ans+=solve();
99             ans%=MOD;
100         }
101     }
102     printf("%lld\n",ans);
103     return 0;
104 }