TP5 universite paris diderot informatique

TP5.java

import java.util.Random;
import java.util.Arrays;

public class TP5
{
  static Random rand = new Random();

  static int randRange(int a, int b)
  {
    return (rand.nextInt(b - a) + a);
  }

  public static void main(String[] args)
  {
    int[][] g = {{0, 1, 0}, {1, 0, 0}, {0, 0, 0}};
    System.out.println(Arrays.deepToString(CreateGraph(5)));
    System.out.println(friends_nbr(g, 0));
    System.out.println(Arrays.toString(friends(g, 0)));
    System.out.println(Arrays.toString(popular(g)));
    int[][] gr = {{0, 1, 1}, {1, 0, 1}, {0, 1, 1}};
    System.out.println(Arrays.toString(common_friends(gr, 0, 1)));
    int[][] gr2 = add_user(gr, new int[]{0, 1, 2, 3});
    System.out.println(Arrays.deepToString(gr2));
    System.out.println(Arrays.toString(popular_noms(g, new String[]{"a", "b", "c"})));
    System.out.println("abc");
  }

  static int[][] CreateGraph(int N)
  {
    int n = randRange(0, N);
    int[][] Graph = new int[N][N];

    while (n != 0)
    {
      int i = randRange(0, N), j = randRange(0, N);
      if (0 == Graph[i][j] && i != j)
      {
        Graph[i][j] = Graph[j][i] = 1;
        n--;
      }
    }

    return Graph;
  }

  static int friends_nbr(int[][] R, int a)
  {
    int ret = 0;

    for (int c : R[a])
      ret += c;

    return ret;
  }

  static int[] friends(int[][] R, int a)
  {
    int[] f = new int[friends_nbr(R, a)];
    int c = 0;

    for (int i = 0; i < R[a].length; i++)
      if (1 == R[a][i])
        f[c++] = i;

    return f;
  }

  static int[] popular(int[][] R)
  {
    int[] ret_tmp = new int[R.length];
    int max_friend = 0;
    int l = 0;

    for (int a = 0; a < R.length; a++)
    {
      int c = friends_nbr(R, a);

      if (c > max_friend)
      {
        l = 1;
        ret_tmp[0] = a;
        max_friend = c;
      }
      else if (c == max_friend)
        ret_tmp[l++] = a;
    }

    int[] ret = new int[l];

    for (; --l >= 0;)
      ret[l] = ret_tmp[l];

    return ret;
  }

  static int[] common_friends(int[][] R, int a, int b)
  {
    int f_a = friends_nbr(R, a), f_b = friends_nbr(R, b);
    int[] f = new int[(f_a > f_b ? f_a : f_b) - R[a][b]];
    int c = 0;

    for (int i = 0; i < R[a].length; i ++)
      if (1 == R[a][i] && 1 == R[b][i])
        f[c++] = i;

    return f;
  }

  static int[][] add_user(int[][] R, int[] t)
  {
    int u = R.length;
    int[][] Ret = new int[u + 1][u + 1];

    for (int i = 0; i < u; i++)
      for (int j = 0; j < u; j++)
        Ret[i][j] = R[i][j];
    for (int f : t)
      if (0 <= f && f < u)
        Ret[f][u] = Ret[u][f] = 1;

    return Ret;
  }

  static String[] popular_noms(int[][] R, String[] noms)
  {
    int[] ret_tmp = new int[R.length];
    int max_friend = 0;
    int l = 0;

    for (int a = 0; a < R.length; a++)
    {
      int c = friends_nbr(R, a);

      if (c > max_friend)
      {
        l = 1;
        ret_tmp[0] = a;
        max_friend = c;
      }
      else if (c == max_friend)
        ret_tmp[l++] = a;
    }

    String[] ret = new String[l];

    for (; --l >= 0;)
      ret[l] = noms[ret_tmp[l]];

    return ret;
  }/*

  static int[] invite(int[][] R, int a)
  {
    int[] ret_tmp = new int[R.length];
    int c = 0;
    for (int i = 0; i < R.length; i++)
      if (1 == R[a][i])
      {
        R[i][a] = 0;
        for (int j = 0; j < R.length; j++)
          if (1 == R[i][j])
          {
            ret_tmp[j] = j;
            c++;
          }
      }

    int[] ret = new int[c];

    for (int i = 0; i < ret_tmp.length; i++)
      if (0 != ret_tmp[i])
  }*/
}