区域中的最大元素

Question

我想比较数组中元素的值与相邻元素（3x3）并找到最大值（数字）。我的代码似乎不起作用。哪部分出了问题？

int data[10][10] = {};
int dataMax[10][10] = {};
int r_size = 3;  // Size of region to compare
int h = floor(r_size/2);    

for(int i = h; i < ( 10 - h  ) ; i++){       
    for(int j = h; j < ( 10 - h ); j++){
      int max = 0;

        for( int ii = i - h; ii < ( i + h ); ii++ ){
            for( int jj = j - h; jj < ( j + h  ); jj++ ){

               if( data[ii][jj] > max ){

                 max = data[ii][jj];

               }else{

                  dataMax[ii][jj] = 0;

                }
            }
        }

   dataMax[ii][jj]  = data[ii][jj];

    }
}

[根据答案编辑]

int data[10][10] = 
{{0,0,3,0,1,0,0,0,0,1},
{0,0,0,2,0,0,0,0,0,0},
{0,0,0,0,0,0,1,1,0,0},
{0,0,0,0,0,0,0,3,0,0},
{0,4,2,0,0,0,0,0,0,0},
{0,1,0,0,0,0,0,0,0,0},
{0,0,0,0,0,0,0,0,0,0},
{0,0,0,0,0,8,1,1,0,0},
{0,0,0,0,3,6,0,0,2,0},
{2,0,0,0,0,0,0,0,0,0}};

int dataMax[10][10] = {};
int r_size = 3;  // Size of region to compare
int h = floor(r_size/2.0);    

for(int i = h; i < ( 10 - h  ) ; i++){        //**** correction ****
   for(int j = h; j < ( 10 - h ); j++){      //**** correction ****
     int max = 0;
     int max_x = 0;              //**** correction ****
     int max_y = 0;

    for( int ii = i - h; ii <= ( i + h ); ii++ ){         //**** correction ****     
        for( int jj = j - h; jj <= ( j + h  ); jj++ ){    //**** correction ****

           if( data[ii][jj] > max ){

             max = data[ii][jj];
             max_x = ii;              //**** correction ****
             max_y = jj;

           }else{

   //           dataMax[ii][jj] = 0;

            }
        }
    }

   dataMax[max_x][max_y]  = max;       //**** correction ****

   }
}

我希望得到以下dataMax：

Answer 1

好吧，有一点是这样的：

int h = floor(r_size/2); 

h现在是1.

和

    for( int ii = i - h; ii < ( i + h ); ii++ ){

在i-1到i+1之间进行迭代，总共进行两次迭代。您应该将其更改为<=三次迭代。

Answer 2

此刻，你写的地方

dataMax[ii][jj]  = data[ii][jj];

变量ii以及jj不再声明。此外：如果您正在寻找，那么您不会将max值存储在任何位置，这应该会发生。

编辑：在您的修改中发现了另一个错误：尝试设置dataMax[max_x][max_y] = max;，因为您混淆了行和列data[max_x][max_y]应该是data[max_y][max_x]到目前为止可以看到。

但无论如何，既然你要存储最大值，为什么不使用它呢？

Answer 3

以下可能有所帮助：（https://ideone.com/xJXzp8）

int getMax(int minx, int maxx, int miny, int maxy)
{
    minx = std::max(minx, 0);
    maxx = std::min(maxx, 10);
    miny = std::max(miny, 0);
    maxy = std::min(maxy, 10);
    int res = data[minx][miny];

    for (int x = minx; x != maxx; ++x) {
        for (int y = miny; y != maxy; ++y) {
            res = std::max(res, data[x][y]);
        }
    }
    return res;
}

void compute()
{
    const int h = 3;  // Size of region to compare

    for (int x = 0; x != 10; ++x) {
        for (int y = 0; y != 10; ++y) {
            dataMax[x][y] = getMax(x - h / 2, x + h - h / 2,
                                   y - h / 2, y + h - h / 2);
        }
    }
}

void filter()
{
    for (int x = 0; x != 10; ++x) {
        for (int y = 0; y != 10; ++y) {
            if (dataMax[x][y] != data[x][y]) {
                dataMax[x][y] = 0;
            }
        }
    }
}