如何在二维数组上正确使用格式化程序

Question

我必须在右侧添加列中二维数组的行的总和。 但是，当我运行代码时，它会添加每列中所有行的总和，直到到达末尾。 像这样：https://i.stack.imgur.com/1QQZT.png 总和是正确的，但假设下降并且每行只有一次。

      public static void main(String[] args) throws IOException
{
    // TODO code application logic here
    File election = new File("voting_2008.txt");
    Scanner sc = new Scanner(election);
    String[] states = new String[51];
    int[][]votes = new int[51][4];
    int[] Totalbystate = new int[votes.length];
    for (int s=0; s < 51; s++)
    {
        states[s] = sc.nextLine();
    }
    for(int c=0; c < 3; c++)
    {
        for(int s=0; s < 51; s++)
        {
            votes[s][c] = sc.nextInt();
        }
    }
    Formatter fmt = new Formatter();
    fmt.format("%20s%12s%12s%12s%21s", "State", "Obama", "McCain", "Other", "Total by state");
    System.out.println(fmt);
    for (int s=0; s < 51; s++)
    {
       fmt = new Formatter();
       fmt.format("%20s", states[s]);
       System.out.print(fmt);
       for(int c=0; c < 3; c++)
       {
           fmt = new Formatter();
           fmt.format("%12d", votes[s][c]);
           System.out.print(fmt);
       }
       for(int row=0; row < votes.length; row++)
       {   
            int sum =0;
           for (int col=0; col < votes[row].length; col++)
           {
              sum = sum + votes[row][col];
           }
          fmt = new Formatter();
            fmt.format("%21d", sum);
            System.out.print(fmt);  
       }

       System.out.println();
    }
}

}

Answer 1

   for(int row=0; row < votes.length; row++)
   {   
        int sum =0;
        for (int col=0; col < votes[row].length; col++)
         {
          sum = sum + votes[row][col];
        }
        fmt = new Formatter();
        fmt.format("%21d", sum);  
        System.out.print(fmt); // You are not printing newline after each vote..
   }

尝试使用 ： - System.out.println(fmt);代替注释代码。

更新：- 不要做上述更改。行不通..确实要进行以下更改。

这就是问题所在。您正在打印total no of votes,51 * 51次。你在另一个循环中有一个循环，它已经运行了 51 次。

所以，为了解决你的问题..从上面的代码中删除外部循环，并保持如下：-

   //for(int row=0; row < votes.length; row++) // Remove this loop
   //{ // Remove this
        int sum =0;
        for (int col=0; col < votes[s].length; col++)
         {
          sum = sum + votes[s][col];
        }
        fmt = new Formatter();
        fmt.format("%21d", sum);  
        System.out.print(fmt);
   //} // Remove this also..

您从最外层循环中获得s值..

更新： - 如果你想要所有选票的总和..对于所有列..

int totalSum = 0;    // Declare a variable outside it..
for (int s=0; s < 51; s++)   // This is the place where the loop started
{
   fmt = new Formatter();
   fmt.format("%20s", states[s]);
   System.out.print(fmt);
   // Other inner loops
    int sum =0;   // Your innerloop that calculates sum of each state..
    for (int col=0; col < votes[s].length; col++)
     {
      sum = sum + votes[s][col];
    }
    totalSum += sum;   // Add sum to `totalSum`
    fmt = new Formatter();
    fmt.format("%21d", sum);  
    System.out.print(fmt);
    // Continue with the outer loop
}