Question

我正在尝试创建一个程序，其中用户首先输入矩阵的大小，然后是每个单元格是占用（o）还是未占用（。）。我如何编写它以便用户输入一整行的占用/未占用输入，而不是使用嵌套for循环逐个单元？

更新

有一个例子是逐个输入项目：

#include <stdio.h>

#define MAX_SIZE 100

int main(void)
{
    char matrix[MAX_SIZE][MAX_SIZE] = { 0 };
    int rows = 0, cols = 0;
    while (rows < 1 || rows > MAX_SIZE)
    {
        printf("What is the number of rows? ");
        scanf("%d", &rows);
    }
    while (cols < 1 || cols > MAX_SIZE)
    {
        printf("What is the number of columns? ");
        scanf("%d", &cols);
    }
    // fill the matrix
    printf("Please, fill the matrix by entering o for occupied or . for unoccupied cell (E for exit)\n");
    int r, c, ch;
    int fulfill = 1;
    for (r = 0; r < rows && fulfill; r++)
    {
        for (c = 0; c < cols && fulfill; c++)
        {
            // clean the input bufer
            while ((ch = getchar()) != '\n' && ch != EOF);
            // read data
            printf("cell [%d, %d] : ", r + 1, c + 1); // or just r, c if you prefer 0..(N-1) indexing
            while (matrix[r][c] != 'o' && matrix[r][c] != '.' && matrix[r][c] != 'E')
            {
                scanf("%c", &matrix[r][c]);
            }
            if (matrix[r][c] == 'E')
            {
                fulfill = 0;
            }
        }
    }
    // output
    printf("\nResult is:\n");
    for (r = 0; r < rows; r++)
    {
        for (c = 0; c < cols; c++)
        {
            printf("%c", matrix[r][c]);
        }
        printf("\n");
    }
}

Answer 1

考虑以下示例：

#include <stdio.h>
#include <stdlib.h>

int main(void)
{
    char** matrix; // now it is a pointer and memory will be allocated after getting values of rows and columns
    int rows = 0, cols = 0;
    while (rows < 1)
    {
        printf("What is the number of rows (should be >= 1)? ");
        scanf("%d", &rows);
    }
    while (cols < 1)
    {
        printf("What is the number of columns (should be >= 1)? ");
        scanf("%d", &cols);
    }
    // part 1 for memory allocation
    matrix = (char**)malloc(sizeof(char*) * rows);
    // fill the matrix
    printf("Please, fill the matrix by entering o for occupied or . for unoccupied cell (other chars will be ignored)\n");
    int r, c, ch;
    for (r = 0; r < rows; r++)
    {
        // part 2 for memory allocation - memory for each row
        matrix[r] = (char*)malloc(sizeof(char) * cols);
        for (c = 0; c < cols; c++)
        {
            // read while apropriate character was found
            while ((ch = getchar()) != 'o' && ch != '.');
            // save character to matrix
            matrix[r][c] = ch;
        }
    }
    // output
    printf("\nResult is:\n");
    for (r = 0; r < rows; r++)
    {
        for (c = 0; c < cols; c++)
        {
            printf("%c", matrix[r][c]);
        }
        printf("\n");
    }
    // free the memory
    for (r = 0; r < rows; r++)
    {
        free(matrix[r]);
    }
    free(matrix);
}

这里数据存储在堆中（动态内存，由malloc或其他类似函数分配），尽管使用相同的嵌套循环输入是不同的。看，它是如何工作的：

What is the number of rows (should be >= 1)? 3
What is the number of columns (should be >= 1)? 3
Please, fill the matrix by entering o for occupied or . for unoccupied cell (other chars will be ignored)
o.o
.o.
o.o

Result is:
o.o
.o.
o.o

用户可以使用Enter键逐行输入以开始新行，或者只为所有单元格逐个输入o和.（在任何情况下都将逐行填充）。不必要的元素以及不适当的字符（与o和.不同）将被忽略。 E.g：

What is the number of rows (should be >= 1)? 4
What is the number of columns (should be >= 1)? 5
Please, fill the matrix by entering o for occupied or . for unoccupied cell (other chars will be ignored)
ooZooCooXooOoo
......
........XXX

Result is:
ooooo
ooooo
.....
.....

C - 用户输入矩阵

1 个答案: