566. 重塑矩陣

int** matrixReshape(int** mat, int matSize, int* matColSize, int r, int c, int* returnSize, int** returnColumnSizes)
{   
    // 條件不滿足，返回原矩陣
    if (r * c != matSize * (*matColSize)) {
        *returnSize = matSize;
        *returnColumnSizes = malloc(sizeof(int) * matSize);
        for (int
 
 i = 0; i < matSize; i++) {
            (*returnColumnSizes)[i] = matColSize[i];
        }
        return mat;
    }

    // 先把2維矩陣，轉成1維
    int *arrayOne = malloc(sizeof(int) * r * c);
    for (int i = 0, count = 0; i < matSize; i++) {
        for (int j = 0; j < *matColSize; j++) {
            arrayOne[count
 
++] = mat[i][j];
        }
    }

    // 再把1維轉成需要的2維矩陣
    // 方法：int**本質就是指向int*的指標，讓它指向1維陣列的不用部位即可
    int **res = malloc(sizeof(int*) * r);
    *returnSize = r;
    *returnColumnSizes = malloc(sizeof(int) * r);
    for (int i = 0; i < r; i++) {
        (*returnColumnSizes)[i] = c;
        // 開始換皮，把1維轉成最終的2維
 

        res[i] = arrayOne + i*c;
    }
    
    return res;
}