启动内核--从“myFirstKernel”模板开始。

Part1：使用指针d_a为内核的结果分配设备内存。
Part2：使用1-D的1-D网格来配置和启动内核
线程块。
Part3：让每个线程设置一个d_a的元素，如下所示：
idx = blockIdx.x * blockDim.x + threadIdx.x d_a [idx] = 1000 * blockIdx.x + threadIdx.x
Part4：将d_a中的结果复制回主机指针h_a。
Part5：验证结果是否正确。(Start the kernel -- start with the myFirstKernel template.
Part1: use pointer d_a to allocate device memory for the results of the kernel.
Part2: use the 1-D 1-D grid to configure and start the kernel
Thread block.
Part3: let each thread set an element of d_a, as shown below:
IDX = blockIdx.x * blockDim.x + threadIdx.x d_a = [idx] = 1000 * blockIdx.x + threadIdx.x
Part4: copy the results from d_a back to the host pointer h_a.
Part5: is the validation correct?.)