c++题解

#include<bits/stdc++.h>
using namespace std;
#define int long long
unordered_map<int,int> cnt;
signed main(){
int x,q;
char op;
cin>>q;
while(q--){
    cin>>op>>x;
    if(op=='I'){
       cnt[x]++;
    }
    if(op=='Q'){
        if(cnt[x]){
            cout<<"Yes"<<endl;
        }
        else cout<<"No"<<endl;
    }
}
}

JAVA ac代码： 送分题，掌握set的运用

import java.util.*;
import java.util.StringTokenizer;
import java.io.*;

public class Main {

	public static void main(String[] args) {
		int q=in.nextInt();
		Set<Integer> set=new HashSet<>();
		while(q-->0){
			String op=in.next();
			int x=in.nextInt();
			if(op.equals("I")){
				set.add(x);
			}else{
				if(set.contains(x)) out.println("Yes");
				else out.println("No");
			}
		}
		out.close();
	}
	
	

	static FastReader in=new FastReader();
	static PrintWriter out=new PrintWriter(System.out);
	static class FastReader{
		static BufferedReader br;
		static StringTokenizer st;
		FastReader(){
			br=new BufferedReader(new InputStreamReader(System.in));
		}
		String next() {
			String str="";
			while(st==null||!st.hasMoreElements()) {
				try {
					str=br.readLine();
				}catch(IOException e) {
					throw new RuntimeException(e);
				}
				st=new StringTokenizer(str);
			}
			return st.nextToken();
		}
		int nextInt() {
			return Integer.parseInt(next());
		}
		double nextDouble() {
			return Double.parseDouble(next());
		}
		long nextLong() {
			return Long.parseLong(next());
		}
	}
	
}