Wannafly挑战赛4. B

 1 #include<bits/stdc++.h>
 2 #define db double
 3 #define ll long long
 4 #define vec vector<ll>
 5 #define Mt  vector<vec>
 6 #define ci(x) scanf("%d",&x)
 7 #define cd(x) scanf("%lf",&x)
 8 #define cl(x) scanf("%lld",&x)
 9 #define pi(x) printf("%d\n",x)
10 #define pd(x) printf("%f\n",x)
11 #define pl(x) printf("%lld\n",x)
12 #define rep(i,x,y) for(int i=x;i<=y;i++)
13 #define debug puts("-------------");
14 const int N = 1e6 + 5;
15 const int mod = 1e9 + 7;
16 const int MOD = mod-1;
17 const db  eps = 1e-18;
18 const db  PI = acos(-1.0);
19 using namespace std;
20 ll a[N];
21 ll d[2][2];
22 int main()
23 {
24     int n,l,r;
25     ci(n),ci(l),ci(r);
26     for(int i=1;i<=n;i++)cin>>a[i],a[i]^=a[i-1];
27     ll ss=0;
28     if(l&1) l++;
29     if(r&1) r--;
30     if(l>r) return 0*puts("0");
31     for(int i=0;i<31;i++)
32     {
33         ll ans=0;
34         memset(d,0, sizeof(d));
35         for(int j=1;j<=n;j++)
36         {
37             if(j>=l) d[(j-l)&1][(a[j-l]>>i)&1]++,ans=(ans+d[j&1][!((a[j]>>i)&1)])%mod;
38             if(j>=r) d[(j-r)&1][(a[j-r]>>i)&1]--;
39         }
40         ss=(ss+ans*(1ll<<i)%mod)%mod;
41     }
42     pl((ss+mod)%mod);
43     return 0;
44 }