洛谷P2114起床困难综合征

 1 /*by SilverN*/
 2 #include<iostream>
 3 #include<cstring>
 4 #include<cstdio>
 5 #include<cmath>
 6 using namespace std;
 7 const int mxn=100020;
 8 int n,m;
 9 int p[35];
10 int op[mxn],a[mxn];
11 int ans=0;
12 int pro(int x){
13     for(int i=1;i<=n;i++){
14         if(op[i]==1)x=x&a[i];
15         else if(op[i]==2)x=x|a[i];
16          else x=x^a[i];
17     }
18     return x;
19 }
20 int main(){
21     scanf("%d%d",&n,&m);
22     int i,j;
23     char c[5];
24     for(i=1;i<=n;i++){
25         scanf("%s%d",c,&a[i]);
26         if(c[0]==‘A‘)op[i]=1;
27         else if(c[0]==‘O‘)op[i]=2;
28          else op[i]=3;
29     }
30     for(i=0;i<=30;i++) p[i]=1<<i;
31     for(i=30;i>=0;i--){
32         if(ans+(1<<i) > m)continue;//只能填0
33         if( pro(1<<i) > pro(0) )ans+=(1<<i);
34     }
35     printf("%d\n",pro(ans));
36     return 0;
37 }