特征提取

字节题是真顶
没办法把数组作为key就把数组转换成String

import java.util.Scanner;
import java.util.*;


public class Main{
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        HashMap<String,ArrayList<Integer>> hash = new HashMap<>();


        int N = sc.nextInt();
        for (int k=0;k<N;k++){
            int n = sc.nextInt();
            for(int i=0;i<n;i ++){
                int m = sc.nextInt();
                for(int j=0;j<m;j++){
                    String key = sc.nextInt() + "_" +sc.nextInt();
                    if(hash.containsKey(key)){
                        ArrayList<Integer> list = hash.get(key);
                        list.add(i);
                    }else{
                        ArrayList<Integer> new_list = new ArrayList<Integer>();
                        new_list.add(i);
                        hash.put(key,new_list);
                    }
                }
            }
            int MAX = 1;
            for(String key: hash.keySet()){
                int max = 1;
                ArrayList<Integer> list = hash.get(key);
                for (int i =1;i< list.size();i++){
                    if(list.get(i) == list.get(i-1)+1) {
                        max++;
                        MAX = Math.max(MAX,max);
                    }
                    else{
                        MAX = Math.max(MAX,max);
                        max = 1;
                    }
                }
            }
            if (hash.size()==0) System.out.println(0);
            else System.out.println(MAX);
        }
    }
}

自己构建hash的算法

链接：https://www.nowcoder.com/questionTerminal/5afcf93c419a4aa793e9b325d01957e2
来源：牛客网

import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int n = scanner.nextInt();
        int ans = 0;
        Map<Reference, Integer> map1 = new HashMap<Reference, Integer>();
        Map<Reference, Integer> map2 = new HashMap<Reference, Integer>();
        for(int i=0;i<n;i++) {
            int m = scanner.nextInt();
            map1.clear();
            for(int j=0;j<m;j++) {
                 int p = scanner.nextInt();
                 if(p==0) {
                     map1.clear();
                     continue;
                 }
                 for(int k=0;k<p;k++) {
                     int x = scanner.nextInt();
                     int y = scanner.nextInt();
                     Reference reference = new Reference(x, y);
                     if(map1.containsKey(reference)) {
                         map2.put(reference, map1.get(reference)+1);
                     }else {
                         map2.put(reference, 1);
                     }
                     ans = Math.max(ans, map2.get(reference));
                 }
                 map1.clear();
                 map1.putAll(map2);
                 map2.clear();
            }
        }
        System.out.println(ans);
    }




}
class Reference{
    int x;
    int y;
    public Reference(int x, int y) {
        super();
        this.x = x;
        this.y = y;
    }
    @Override
    public int hashCode() {
        return  x + y + x*y;
    }
    @Override
    public boolean equals(Object obj) {
        Reference reference = (Reference)obj;
        return x==reference.x && y==reference.y;
    }

}