How can line-by-line input be implemented in the C lang…

In C language, the scanf() function can be used for taking input line by line. This function is a formatted input function that reads data from the standard input stream (i.e. keyboard).

Here is a sample code demonstrating how to implement multiline input:

#include <stdio.h>

int main() {
    int num1, num2;
    
    printf("请输入第一个数：");
    scanf("%d", &num1);
    
    printf("请输入第二个数：");
    scanf("%d", &num2);
    
    printf("您输入的两个数分别是：%d 和 %d\n", num1, num2);
    
    return 0;
}

When running the code above, the program will first prompt the user to enter two numbers separately, and then store them in variables num1 and num2 after the user input. Finally, the program will print out the two numbers input by the user.

Please note that the scanf() function uses the %d format specifier to indicate that the input data type is an integer. If the user enters a non-numeric character, the program may encounter errors. Therefore, error handling is necessary when dealing with user input in real-world applications.