Question

Problem 1
        Write a Java program that implements a two-dimensional array of grades
        for students in a class. The grades should be as follows:
        Row 1: 87, 45
        Row 2: 69, 88, 90, 94
        Row 3: 79, 87, 94
        
        Compute and print out the maximum number of columns in the array.
        Hint: use a for loop.
        
   (5 Points.)
*/

/*      Problem 2
*       Suppose there are 4 candidates in 6 districts running for an election.
    Let's assume the candidates' names are: Jane, Amani, Doe, and Macbeth.
        Your task is to print out: 1) the total votes per candidate, and 2) the
        total votes per district.
        
        Here are some hints:
        1) Create a two-dimensional array of type int and name it ballots.
         int [][] ballots = { }. Fill it with votes. Remember, you are going to have
         four columns and six rows.
         
        2) Create the candidates as follows: String [] candidates = { } and
        assign them names.
        
        3) Create an object reference to hold the tally for the votes.
        
        4) Use a for loop to print the totals for candidates. 
        
        5) Use a for loop to print the totals for districts.
        
        Your output should look like:
        Total votes per candidate
        Jane
        x
        
        Amani
        x
        
        Doe
        x
        
        Macbeth
        x
        
        Total votes per district
        1
        x
        
        2
        x
        
        3
        x
        
        4
        x
        
        5
        x
        
        6
        x
*       (10 Points.)

Answer 1

solutions for Problem 1

import java.util.*;
class Problem1
{
   public static void main(String args[])
   {
   Scanner sc=new Scanner(System.in);
   int row=2;
   System.out.println("Enter maximum number of columns in the array : ");
   int col=sc.nextInt();
   // array declaration
   int a[][]=new int[row][col];       
   System.out.print("Enter " + row*col + " Grades to Store in Array :\n");
for (int i = 0; i < row; i++)
   {
   for(int j = 0; j < col; j++)
   {
    a[i][j] = sc.nextInt();
   }
   }   
System.out.print("Grades in Array are :\n");
for (int i = 0; i < row; i++)
   {
           System.out.print("Row "+(i+1)+":");

   for(int j = 0; j < col; j++)
   {
   System.out.print(a[i][j]+", ");
    }
       System.out.println();
   }
   }
}

Screen shot of the code

Problem 2 solution:

public class Problem2
{
public static void main(String[] args) {
int sumRow, sumCol;
//Initialize candidates
       String [] candidates = {"Jane", "Amani", "Doe", "Macbeth"};
       // initialize matrix[6][4] with votes
       int [][]ballots ={
                           {10000,10003,100004,2343},
                           {42343,535,4535,5656},
                           {676,877,323,3435},
                           {6667,2334,5565,2324},
                           {456,790,907,433},
                           {223,545,565,767}};
for(int i = 0; i < 6; i++){
sumRow = 0;
for(int j = 0; j < 4; j++){
sumRow = sumRow + ballots[i][j];
}
System.out.println("Total votes per district " + (i+1) +":" + sumRow);
}
       System.out.println("*********************************");
  
for(int i = 0; i < 4; i++){
sumCol = 0;
for(int j = 0; j < 6; j++){
sumCol = sumCol + ballots[j][i];
}
System.out.println("Total votes per candidate " + candidates[i] +": " + sumCol);
}
}
}