1 #include<stdio.h>
 2 #include<algorithm>
 3 using namespace std;
 4 int n,m,a[200001];
 5 inline int getint() {
 6     int x=0,f=1; char c;
 7     c=getchar();
 8     while(c<'0'||c>'9') {if (c=='-') f=-1; c=getchar();}
 9     while(c>='0'&&c<='9') {x=(x<<3)+(x<<1)+c-'0';c=getchar();}
10     return x*f;
11 }
12 int main() {
13     n=getint();m=getint();
14     for (int i=1;i<=n;++i)a[i]=getint();
15     sort(a+1,a+n+1);
16     bool f=0;
17     for (int i=1;i<=m;++i,f=0) {
18         int x,l=1,r=n; x=getint();
19         while(l<=r) { //cout<<l<<' '<<r<<endl;
20             if(a[l]==x||a[r]==x) {f=1; break;}
21             int mid=(l+r)>>1;
22             if(a[mid]==x) {f=1;break;}
23             if(x<a[mid]) r=mid-1;
24             else if(x>a[mid]) l=mid+1;
25         }
26         if(f) printf("Y");
27         else printf("N");
28     }
29     printf("\n");
30     return 0;
31 }

 1 #include<stdio.h>
 2 #include<map>
 3 #include<algorithm>
 4 using namespace std;
 5 int n,m;
 6 map<int,bool> a;
 7 inline int getint() {
 8     int x=0,f=1; char c;
 9     c=getchar();
10     while(c<'0'||c>'9') {if (c=='-') f=-1; c=getchar();}
11     while(c>='0'&&c<='9') {x=(x<<3)+(x<<1)+c-'0';c=getchar();}
12     return x*f;
13 }
14 int main() {
15     n=getint();m=getint();
16     for (int i=1;i<=n;++i) {
17         int x;x=getint();
18         a[x]=1;
19     }
20
21     bool f=0;
22     for (int i=1;i<=m;++i,f=0) {
23         int x,l=1,r=n; x=getint();
24         if(a[x]==1) printf("Y");
25         else printf("N");
26     }
27     printf("\n");
28     return 0;
29 }