Submission #7052043

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Source Code Expand

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		final int N = sc.nextInt();
		final int M = sc.nextInt();

		final int friendLength = N*(N-1)/2;
		final boolean[] isFriend = new boolean[friendLength];
		for (int i = 0; i < M; i++) {
			int xi = sc.nextInt();
			int yi = sc.nextInt();
			isFriend[(2*N-xi-2)*(xi-1)/2 + yi-2] = true;
		}
		sc.close();

		int intOut = 1;
		int x;
		int y;
		A: for(int bitNumber = 1; bitNumber <= (1 << N) - 1; bitNumber++){
			int groupL = Integer.bitCount(bitNumber);
			if(groupL <= intOut){
				continue;
			}

			boolean flag = true;
			for(x = 0; x <= N - 2; x++){
				for(y = x + 1; y <= N - 1; y++){
					if(((bitNumber >> x) & (bitNumber >> y) & 1) == 1){
						if(!isFriend[(2*N-x-3)*x/2 + y-1]){
							flag = false; continue A;
						}
					}
				}
			}
			if(flag){
				intOut = groupL;
			}

		}

		String strOut = Integer.toString(intOut);
		System.out.println(strOut);
	}
}

Submission Info

Judge Result