Question

好吧，我正在尝试添加二维数组的列的总和，但到目前为止我能够添加总和但不是其他3列。有谁可以告诉我我做错了什么？

here is picture of my output

    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][3];


    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);
    int TotalSum; 
    TotalSum = 0;
    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);

       }


           int sum =0;
           for (int col=0; col < votes[s].length; col++)
           {
              sum = sum + votes[s][col];

           }

           TotalSum += sum;
           fmt = new Formatter();
            fmt.format("%21d", sum);
            System.out.print(fmt); 



       System.out.println();

    }
    Formatter fmt2 = new Formatter();
    fmt2.format("%20s%12s%12s%12s%21s", "Total", "", "", "", TotalSum);
    System.out.print( fmt2 );
}

}

Answer 1

一些简单的更改可以解决您的问题：

1＆GT;将前两个for循环合并为：

    for (int s=0; s < 2; s++){
        states[s] = sc.next();
        for(int c=0; c < 3; c++) {
            votes[s][c] = sc.nextInt();
        }
    }

在TotalSum旁边定义一个新的colSum []，如下所示：
```
int TotalSum = 0;
int colSum[] = new int[]{0,0,0};
```

更新投票打印循环以执行列总和：

   for(int c=0; c < 3; c++) {
       colSum[c]+=votes[s][c]; // <-- new line to do the column sum
       fmt = new Formatter();
       fmt.format("%12d", votes[s][c]);
       System.out.print(fmt);
   }

将最后一行的列总和打印为：

    fmt2.format("%20s%12s%12s%12s%21s", "Total", colSum[0], colSum[1], colSum[2], TotalSum);
    System.out.print( fmt2 );

希望这会有所帮助!!

Answer 2

你的逻辑有点偏。

在第一次for循环之后：

for (int s=0; s < 51; s++)
{
    states[s] = sc.nextLine();
}

您已经消耗了文件中的前50行，并且“states”数组中的每个元素都包含每行的文本。下次您尝试从扫描仪读取时，您将在第51行，因此您只需阅读文件底部的总计，如您最初所述。

我认为您想要做的是每个州（文件中的每一行）将数字列1,2和3加在一起？

以下是一些应该有用的示例代码：

File election = new File("voting_2008.txt");

Scanner scanner = new Scanner(election);

String[] states = new String[50]; // 50 united states
int[] votes = new int[50];

// only grab the first 50 lines, each line a different state
// assuming file layout is: stateName,count1,count2,count3
for ( int i = 0; i < 51; i++ ) {

    states[i] = scanner.next();

    // grab the next 3 numbers
    int voteTotal = 0;
    for ( int j = 0; j < 3; j++ ) {
        voteTotal += scanner.nextInt(); 
    }
    votes[i] = voteTotal; // total votes for this state

}

// ... display results ..

如何在java中对2维数组的列求和

2 个答案: