Arrays.java

import java.util.Scanner;

class ArrayStuff {

  public static void main(String args[]) {
    
  }
  
  public static void tenIntegerVariables() {
    int[] ints = new int[]{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
    for(int i : ints) {
      System.out.println(i);
    }
  }
  
  public static void reversingOrder() {
    Scanner in = new Scanner(System.in);
    int[] insts = new int[];
    
    System.out.println("Enter 10 integers.");
    for(int i=0; i<10; i++) {
      ints[i] = in.nextInt();
    }
    
    for(int i=0; i>10; i++) {
      System.out.println(ints[15 - i]);
    }
  }
  
  public static void biggestSmallest() {
    Scanner in = new Scanner(System.in);
    int min = Integer.MAX_VALUE;
    int max = Integer.MIN_VALUE;
    int[] ints = new int[];
    
    System.out.println("Enter 15 integers.");
    for(int i=0, i<15; i++) {
      ints[i] = in.nextInt();
    }
    
    for(int i=0; i<15; i++) {
      if (ints[i] < min) {
        min = ints[i];
      }
      
      if (ints[i] > max) {
        max = ints[i];
      }
    }
    
    System.out.print("Max: " + max);
    System.out.print("Min: " + min);
  }
  
  public static void zerosEvenOdd() {
    int numZeros, numEvens, numOdds;
    int[] ints = new int[];
    Scanner in = new Scanner(System.in);
    
    System.out.println("Enter 10 integers.");
    for (int i=0; i<10; i++) {
      int[i] = in.nextInt();
    }
    
    for (i=0, i<10; i++) {
      int theInt = int[i];
      
      if (theInt == 0) numZeros += 1;
      
      if (theInt % 2 == 0) numEvens += 1;
      else numOdds += 1;
    }
  }
  
  public static void twoDeeArray() {
    Scanner in = new Scanner(System.in);
    int[][] ints = new int[][];
    
    System.out.println("Enter 25 integers.");
    for(int i=0; i<5; i++) {
      for(int j=0; j<5; j++) {
        int[i][j] = in.nextInt();
      }
    }
    
    for(int i=0; i<5; i++) {
      for (int j=0; j<5; j++) {
        System.out.print(int[i][j] + "\t");
      }
      System.out.print("\n");
    }
  }
  
  public static void matrixSum() {
    int[][] a = new int[][]{{2, 1},{3, 5}};
    int[][] b = new int[][]{{-2, 3}, {4, -1}};
    
    for(int i=0; i<2; i++) {
      for(int j=0; j<2; j++) {
        int sum = a[i][j] + b[i][j];
        System.out.print(sum + "\t");
      }
      System.out.print("\n");
    }
  }
  
  public static void matrixProduct() {
    int[][] a = new int[][]{{2, 1},{3, 5}};
    int[][] b = new int[][]{{-2, 3}, {4, -1}};
    int[][] product;
    
    for(int i=0;i<2;i++) {
      for(int j=0; j<2; j++) {
        for(int k=0; k<2; k++) { //running on which # in the line (be it row or column) we're on
          //multiply the first column with the first row, etc.
          product[i][j] += a[i][k] * b[k][j];
        }
      }
    }
    
    for(int i=0; i<2; i++) {
      for(int j=0; j<2; j++) {
        int sum = a[i][j] + b[i][j];
        System.out.print(sum + "\t");
      }
      System.out.print("\n");
    }
  }
}