2015湖南ACM省赛I题 Internet of Lights and Switches（思维）

 1 #define bug(x) cout<<#x<<" is "<<x<<endl
 2 #include<iostream>
 3 #include<algorithm>
 4 #include<iterator>
 5 #include<vector>
 6 #include<set>
 7 #define iter ::iterator
 8 using namespace  std;
 9 #define ll long long
10 const int N=3e5+5;
11 int n,m,L,R;
12 ll a[N],b[N],c[N];
13 char s[100];
14 ll cal(){
15     ll h=1;
16     ll res=0;
17     for(int i=n;i>=1;i--){
18         if(s[i]==‘1‘){
19             res+=h;
20         }
21         h<<=1;
22     }
23     return res;
24 }
25 vector<int>v[N];
26 int main(){
27     int kase=0;
28     ll z=1;
29     while(scanf("%d%d%d%d",&n,&m,&L,&R)!=EOF){
30         ll k=(z<<n)-1;
31         for(int i=1;i<=m;i++){
32             scanf("%s",s+1);
33             a[i]=cal();
34             c[i]=a[i]^c[i-1];
35             b[i]=c[i];
36         }
37         sort(b+1,b+1+m);
38         int nb=unique(b+1,b+1+m)-b-1;
39         for(int i=1;i<=m;i++){
40             a[i]=lower_bound(b+1,b+1+nb,c[i])-b;
41             v[a[i]].push_back(i);
42         }
43         for(int i=1;i<=nb;i++){
44             sort(v[i].begin(),v[i].end());
45         }
46         ll ans=0;
47         for(int i=0;i<=m;i++){
48             if(i+L>m)break;
49             ll x=c[i];
50             x^=k;
51             int id=lower_bound(b+1,b+1+nb,x)-b;
52             if(id>nb)continue;
53             if(b[id]!=x)continue;
54             int res=upper_bound(v[id].begin(),v[id].end(),i+R)-lower_bound(v[id].begin(),v[id].end(),i+L);
55             ans+=res;
56         }
57         printf("Case %d: %lld\n",++kase,ans);
58         for(int i=1;i<=nb;i++)v[i].clear();
59     }
60 }
61 /*
62 2 4 1 4
63 01
64 10
65 11
66 00
67 2 4 3 3
68 01
69 10
70 11
71 00
72 6 3 1 3
73 101001
74 010110
75 101001
76 */