【链接】

【题意】

让你找到所有和x颜色的点中,和该颜色的点颜色不同的相邻的点的个数(重复颜色算一次)

求出哪种颜色的所要求的点的数量最多.

【题解】

对于每一条边只会被查到两次。

所以按照题意暴力枚举的时间复杂度就是O(n+m)级别的

至于查重 只要对找过的点打个标记就很好处理的

【代码】

import java.io.*;import java.util.*;public class Main {        static InputReader in;    static PrintWriter out;            public static void main(String[] args) throws IOException{        //InputStream ins = new FileInputStream("E:\\rush.txt");        InputStream ins = System.in;        in = new InputReader(ins);        out = new PrintWriter(System.out);        //code start from here        new Task().solve(in, out);        out.close();    }        static int N = (int)1e5;    static class Task{                int n,m;        int c[] = new int[N+10];        ArrayList
    
      g[] = new ArrayList[N+10];        ArrayList
     
       col[] = new ArrayList[N+10];        int mark[] = new int[N+10];                public void solve(InputReader in,PrintWriter out) {            for (int i = 1;i <= N;i++) g[i] = new ArrayList
      
       ();            for (int i = 1;i <= N;i++) col[i] = new ArrayList
       
        ();            n = in.nextInt();m = in.nextInt();            for (int i = 1;i <= n;i++) {                c[i] = in.nextInt();                col[c[i]].add(i);            }            for (int i = 1;i <= m;i++) {                int x,y;                x = in.nextInt();y = in.nextInt();                g[x].add(y);g[y].add(x);            }            int ans = -1,idx = 0;            for (int i = 1;i <= N;i++)                if (!col[i].isEmpty()) {                    int cnt = 0;                    for (int J = 0;J < (int)col[i].size();J++) {                        int x = col[i].get(J);                        int len = g[x].size();                        for (int j = 0;j < len;j++) {                            int y = g[x].get(j);                            if (c[y]!=c[x]) {                                if (mark[c[y]]!=i) {                                    cnt++;                                    mark[c[y]] = i;                                }                            }                        }                    }                    if (cnt>ans) {                        ans = cnt;                        idx = i;                    }                }            out.println(idx);        }    }        static class InputReader{        public BufferedReader br;        public StringTokenizer tokenizer;                public InputReader(InputStream ins) {            br = new BufferedReader(new InputStreamReader(ins));            tokenizer = null;        }                public String next(){            while (tokenizer==null || !tokenizer.hasMoreTokens()) {                try {                tokenizer = new StringTokenizer(br.readLine());                }catch(IOException e) {                    throw new RuntimeException(e);                }            }            return tokenizer.nextToken();        }                public int nextInt() {            return Integer.parseInt(next());        }    }}