UVA 11527 Unique Snowflakes

用STL做会很方便

SET:

 /*by SilverN*/
 #include<iostream>
 #include<algorithm>
 #include<cstring>
 #include<cstdio>
 #include<cmath>
 #include<set>
 using namespace std;
 const int mxn=;
 int a[mxn];
 int n,T;
 int main(){
     scanf("%d",&T);
     int i,j;
     while(T--){
         scanf("%d",&n);
         for(i=;i<=n;i++)scanf("%d",&a[i]);
         set<int>s;
         int L=,R=;
         int ans=;
         while(R<=n){
             while(R<=n && !s.count(a[R])) s.insert(a[R++]);
             ans=max(ans,R-L);
             s.erase(a[L++]);
         }
         printf("%d\n",ans);
     }
     return ;
 }

MAP:

 /*by SilverN*/
 #include<iostream>
 #include<algorithm>
 #include<cstring>
 #include<cstdio>
 #include<cmath>
 #include<map>
 using namespace std;
 const int mxn=;
 int a[mxn];
 int last[mxn];
 map<int,int>cur;
 int T,n;
 int main(){
     scanf("%d",&T);
     while(T--){
         scanf("%d",&n);
         int i,j;
         cur.clear();
         for(i=;i<=n;i++){
             scanf("%d",&a[i]);
             //预处理
             if(!cur.count(a[i]))last[i]=-;
             else last[i]=cur[a[i]];
             cur[a[i]]=i;
         }
         int L=,R=;
         int ans=;
         while(R<=n){
             while(R<=n && last[R]<L)R++;
             ans=max(ans,R-L);
             L++;
         }
         printf("%d\n",ans);
     }
     return ;
 }