包含整数的二维矩阵 M 表示一个图片的灰度。你需要设计一个平滑器来让每一个单元的灰度成为平均灰度 (向下舍入) ,平均灰度的计算是周围的8个单元和它本身的值求平均,如果周围的单元格不足八个,则尽可能多的利用它们。
示例 1:
输入:
[[1,1,1],
[1,0,1],
[1,1,1]]
输出:
[[0, 0, 0],
[0, 0, 0],
[0, 0, 0]]
解释:
对于点 (0,0), (0,2), (2,0), (2,2): 平均(3/4) = 平均(0.75) = 0
对于点 (0,1), (1,0), (1,2), (2,1): 平均(5/6) = 平均(0.83333333) = 0
对于点 (1,1): 平均(8/9) = 平均(0.88888889) = 0
注意:
- 给定矩阵中的整数范围为 [0, 255]。
- 矩阵的长和宽的范围均为 [1, 150]。
/**
* Return an array of arrays of size *returnSize.
* The sizes of the arrays are returned as *returnColumnSizes array.
* Note: Both returned array and *columnSizes array must be malloced, assume caller calls free().
*/
int** imageSmoother(int** M, int MSize, int* MColSize, int* returnSize, int** returnColumnSizes){
if (MSize == 1 && *MColSize == 1){
*returnSize = 1;
** returnColumnSizes = 1;
return M;
}
int **res = (int**)malloc(sizeof(int*)*MSize);
*returnSize = MSize;
for (int i = 0; i < MSize; i++){
res[i] = (int*)malloc(sizeof(int)*(*MColSize));
(*returnColumnSizes)[i] = *MColSize;
}
for (int i = 0; i < MSize; i++)
for (int j = 0; j < *MColSize; j++)
if (MSize == 1)
res[i][j] = M[i][j];
else if (i == 0 && MSize>1)
res[i][j] = M[i][j] + M[i + 1][j];
else if (i != 0 && i + 1 < MSize)
res[i][j] = M[i][j] + M[i – 1][j] + M[i + 1][j];
else if (i != 0 && i + 1 == MSize)
res[i][j] = M[i][j] + M[i – 1][j];
for (int i = 0; i < MSize; i++)
for (int j = 0; j < *MColSize; j++)
if (*MColSize == 1)
M[i][j] = res[i][j];
else if (j == 0 && *MColSize>1)
M[i][j] = res[i][j] + res[i][j + 1];
else if (j != 0 && j + 1 < *MColSize)
M[i][j] = res[i][j] + res[i][j – 1] + res[i][j + 1];
else if (j != 0 && j + 1 == *MColSize)
M[i][j] = res[i][j] + res[i][j – 1];
for (int i = 0; i < MSize; i++)
for (int j = 0; j < *MColSize; j++)
if ((MSize == 1 || *MColSize == 1) && (i + j == 0 || i + j + 2 == MSize + *MColSize))
res[i][j] = M[i][j] / 2;
else if ((MSize == 1 || *MColSize == 1) && (i + j > 0 && i + j + 2 < MSize + *MColSize))
res[i][j] = M[i][j] / 3;
else if ((MSize > 1 && *MColSize > 1) && ((i + j == 0) || (i + j + 2 == MSize + *MColSize) || (i == 0 && j == *MColSize – 1) || (i == MSize – 1 && j == 0)))
res[i][j] = M[i][j] / 4;
else if ((MSize > 2 && *MColSize > 2) && (i > 0 && i < MSize – 1 && j>0 && j < *MColSize – 1))
res[i][j] = M[i][j] / 9;
else
res[i][j] = M[i][j] / 6;
return res;
}