我正在尝试将我的矩阵2by2平方矩阵分段。但我得到了编译错误，不知道为什么。我的代码：
int main()
{
int rowsize,n,i,j,l,k, var=0,var2=0,count = 0,square2by2[2][2];
printf("Size of square matrix: " );
scanf("%d",&n);
rowsize=n;
int *matrix = (int *)malloc(rowsize * rowsize * sizeof(int));
for (i = 0; i < rowsize; i++)
for (j = 0; j < rowsize; j++)
*(matrix + i*rowsize + j) = ++count;
for (i = 0; i < rowsize; i++)
{
for (j = 0; j < rowsize; j++)
{
printf("%d ", *(matrix + i*rowsize + j));
}
printf("\n");
}
for( i=0, l=var2 ;i<2 , l<var2+rowsize ;i++,l++)
{
for( j=0 , k=var ; j<2, k<var+2 ;j++,k++)
{
square2by2[i][j]=matrix[l][k]; // error line
}
if(i==1)
{
var++;
if(var==rowsize-1)
{
printf("\n");
for(int x=0;x<2;x++)
{
printf("\n");
for(int y=0;y<2;y++)
{
printf("%d\t",square2by2[x][y]);
}
}
var = 0;
i-=2;
l-=1;
if(l==rowsize+1)
{
break;
}
}
else
{
i-=2;
l-=2;
printf("\n");
for(int x=0;x<2;x++)
{
printf("\n");
for(int y=0;y<2;y++)
{
printf("%d\t",square2by2[x][y]);
}
}
}
}
return 0;
}
，错误是
37 36 [错误]数组下标的类型'int [int]'无效 为什么我会收到此错误？
答案 0 :(得分：1)
问题是您对#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/gpio.h>
#include <libopencm3/stm32/usart.h>
#include <libopencm3/cm3/nvic.h>
#include <libopencm3/stm32/dma.h>
void clock_setup(void)
{
rcc_clock_setup_hse_3v3(&hse_8mhz_3v3[CLOCK_3V3_168MHZ]);
rcc_periph_clock_enable(RCC_GPIOA);
rcc_periph_clock_enable(RCC_USART2);
rcc_periph_clock_enable(RCC_DMA1);
}
void gpio_setup(void)
{
gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO2 | GPIO3);
gpio_set_af(GPIOA, GPIO_AF7, GPIO2 | GPIO3);
}
void usart_setup(int baud)
{
usart_set_baudrate(USART2, baud);
usart_set_databits(USART2, 8);
usart_set_stopbits(USART2, USART_STOPBITS_1);
usart_set_mode(USART2, USART_MODE_TX_RX);
usart_set_parity(USART2, USART_PARITY_NONE);
usart_set_flow_control(USART2, USART_FLOWCONTROL_NONE);
usart_enable(USART2);
}
void dma_request_setup(void)
{
dma_stream_reset(DMA1, DMA_STREAM5);
nvic_enable_irq(NVIC_DMA1_STREAM5_IRQ);
dma_set_peripheral_address(DMA1, DMA_STREAM5, (uint32_t) &USART2_DR);
dma_set_transfer_mode(DMA1, DMA_STREAM5, DMA_SxCR_DIR_PERIPHERAL_TO_MEM);
dma_set_peripheral_size(DMA1, DMA_STREAM5, DMA_SxCR_PSIZE_8BIT);
dma_set_memory_size(DMA1, DMA_STREAM5, DMA_SxCR_MSIZE_8BIT);
dma_set_priority(DMA1, DMA_STREAM5, DMA_SxCR_PL_VERY_HIGH);
dma_disable_peripheral_increment_mode(DMA1, DMA_SxCR_CHSEL_4);
dma_enable_memory_increment_mode(DMA1, DMA_STREAM5);
dma_disable_transfer_error_interrupt(DMA1, DMA_STREAM5);
dma_disable_half_transfer_interrupt(DMA1, DMA_STREAM5);
dma_disable_direct_mode_error_interrupt(DMA1, DMA_STREAM5);
dma_disable_fifo_error_interrupt(DMA1, DMA_STREAM5);
dma_enable_transfer_complete_interrupt(DMA1, DMA_STREAM5);
}
void dma_transmit_setup(void)
{
dma_stream_reset(DMA1, DMA_STREAM6);
nvic_enable_irq(NVIC_DMA1_STREAM6_IRQ);
dma_set_peripheral_address(DMA1, DMA_STREAM6, (uint32_t) &USART2_DR);
dma_set_transfer_mode(DMA1, DMA_STREAM6, DMA_SxCR_DIR_MEM_TO_PERIPHERAL);
dma_set_peripheral_size(DMA1, DMA_STREAM6, DMA_SxCR_PSIZE_8BIT);
dma_set_memory_size(DMA1, DMA_STREAM6, DMA_SxCR_MSIZE_8BIT);
dma_set_priority(DMA1, DMA_STREAM6, DMA_SxCR_PL_VERY_HIGH);
dma_disable_peripheral_increment_mode(DMA1, DMA_SxCR_CHSEL_4);
dma_enable_memory_increment_mode(DMA1, DMA_STREAM6);
dma_disable_transfer_error_interrupt(DMA1, DMA_STREAM6);
dma_disable_half_transfer_interrupt(DMA1, DMA_STREAM6);
dma_disable_direct_mode_error_interrupt(DMA1, DMA_STREAM6);
dma_disable_fifo_error_interrupt(DMA1, DMA_STREAM6);
dma_enable_transfer_complete_interrupt(DMA1, DMA_STREAM6);
}
void dma_request(void* buffer, const int datasize)
{
dma_set_memory_address(DMA1, DMA_STREAM5, (uint32_t) buffer);
dma_set_number_of_data(DMA1, DMA_STREAM5, datasize);
dma_channel_select(DMA1, DMA_STREAM5, DMA_SxCR_CHSEL_4);
dma_enable_stream(DMA1, DMA_STREAM5);
signal_host();
usart_enable_rx_dma(USART2);
}
void dma_transmit(const void* buffer, const int datasize)
{
dma_set_memory_address(DMA1, DMA_STREAM6, (uint32_t) buffer);
dma_set_number_of_data(DMA1, DMA_STREAM6, datasize);
dma_channel_select(DMA1, DMA_STREAM6, DMA_SxCR_CHSEL_4);
dma_enable_stream(DMA1, DMA_STREAM6);
usart_enable_tx_dma(USART2);
}
int dma_done(void)
{
return !((DMA1_S5CR | DMA1_S6CR) & 1);
}
void dma1_stream5_isr(void) {
usart_disable_rx_dma(USART2);
dma_clear_interrupt_flags(DMA1, DMA_STREAM5, DMA_TCIF);
dma_disable_stream(DMA1, DMA_STREAM5);
}
void dma1_stream6_isr(void) {
usart_disable_tx_dma(USART2);
dma_clear_interrupt_flags(DMA1, DMA_STREAM6, DMA_TCIF);
dma_disable_stream(DMA1, DMA_STREAM6);
}
void signal_host(void) {
usart_send_blocking(USART2, '\n');
}
int main(void)
{
clock_setup();
gpio_setup();
usart_setup(921600);
dma_transmit_setup();
dma_request_setup();
unsigned char buf[16];
dma_request(buf, 16); while (!dma_done());
buf[10] = 'd';
buf[11] = 'a';
buf[12] = 'w';
buf[13] = 'n';
dma_transmit(buf, 16); while (!dma_done());
while(1);
return 0;
}
的声明：
matrix这声明int *matrix = ...
是指向matrix的指针，或者等效地指向一维int数组的指针。因此，int表达式matrix[l]是有价值的。您无法将第二个int索引应用于[k]。
要做你正在尝试做的事情，你需要一个指向二维数组的指针。以下是如何做到这一点：
int此处int a[dim1][dim2];
int (*p)[dim2] = a; // The parentheses are necessary!
是指向p的指针，因此您可以像引用a一样引用p，例如a。
答案 1 :(得分：0)
矩阵已声明为int *，但正用作int [] []
要修复，请使用
square2by2[i][j]=matrix[l * rowsize + k];