Question

我试图根据最后一列的值以降序对2d数组排序。我的代码如下：

#include <stdio.h>
#define totrow 10
#define totcolumn 6
float grade[totrow][totcolumn];
void reArg (float grade[][totcolumn]);

void reArg (float grade[][totcolumn])
{
   int temp, x, k = 5;

   for (int r = 0; r < totrow; r++)
   {
      for (int c = 0; c <totcolumn;c++)
      {
          if (grade[r][k] > grade[c][k])
          {
              for(x = 0; x < totcolumn;x++)
              {
                  temp = grade[r][x];
                  grade[r][x]=grade[c][x];
                  grade[c][x]=temp;
              }
          }
      }
   }
   for (int r = 0; r < totrow; r++)
   {
       for (int c = 0; c < totcolumn; c++)
       {
           printf("%.2f\t",grade[r][c]);
       }
       printf("\n");
   }
}

代码编译后，我得到了我的数组：

7899.00 92.00 90.00 88.00 86.00 89.00
6814.00 85.00 86.00 92.00 88.00 87.00
8234.00 77.00 87.00 84.00 98.00 86.00
7654.00 76.00 87.00 84.00 88.00 83.00
3534.00 86.00 81.00 84.00 73.00 81.00
7284.00 56.00 81.00 87.00 98.00 80.00
9901.00 45.00 78.00 79.00 80.00 70.00
6465.00 87.00 54.00 68.00 72.00 70.00
7934.00 76.00 91.00 84.00 65.00 79.00
7234.00 76.00 81.00 84.00 78.00 79.00

原始数组为：

6814.00 85.00 86.00 92.00 88.00 87.75
7234.00 76.00 81.00 84.00 78.00 79.75
6465.00 87.00 54.00 68.00 72.00 70.25
7899.00 92.00 90.00 88.00 86.00 89.00
9901.00 45.00 78.00 79.00 80.00 70.50
8234.00 77.00 87.00 84.00 98.00 86.50
7934.00 76.00 91.00 84.00 65.00 79.00
7284.00 56.00 81.00 87.00 98.00 80.50
7654.00 76.00 87.00 84.00 88.00 83.75
3534.00 86.00 81.00 84.00 73.00 81.00

为什么程序只对前6行排序？

完整的代码是：https://repl.it/@ryanw123/project-4

Answer 1

问题是您使用的是for(int c = 0; c < totcolumn; c++)，但是，正如我认为您试图制作一个Bubble Sort一样，您需要遍历两次行，例如：for(int c = 0; c < totrow; c++)

我创建了一个在本地运行的示例。

#include <stdio.h>
#define totrow 4
#define totcolumn 2


void reArg (float grade[][totcolumn]) {
   int temp, x, k = 5;

   for (int r = 0; r < totrow; r++) {
      for (int c = 0; c < totrow; c++) {
          if (grade[r][k] > grade[c][k]) {
              for(x = 0; x < totcolumn ; x++) {
                  temp = grade[r][x];
                  grade[r][x]=grade[c][x];
                  grade[c][x]=temp;
              }
          }
      }
   }

   for (int r = 0; r < totrow; r++) {
       for (int c = 0; c < totcolumn; c++) {
           printf("%.2f\t",grade[r][c]);
       }
       printf("\n");
   }
}


int main() {

    float grade[totrow][totcolumn] = {{1,2},{3,4},{0,0}};

    reArg(grade);

    return 0;
}

根据C中2d数组中列的值重新排列行

1 个答案: