how to read input until empty line in C

Question

I am still a beginner to C. I am trying to write a program that reads input (test case) until an empty line is reached.

for example, input is the following:

2
1 2
2 5
3 6

2 3
1 7

the first number stands for the number of test cases. in the output there should be sums of the numbers on each line. OUTPUT:

3
7
9

5
8

and there should be an empty line between them like in the example output.

#include <stdio.h>

typedef struct {
    int a;
    int b;
} A;

int main() {
    int n, i = 0;
    A nums[100];
    scanf("%d\n", &n);
    while(n--){
        while(empty line not reached){
            scanf("%d %d", &nums[i].a, &nums[i].b);
            i++;
        }
        for(int j = 0; j < i; j++) printf("%d\n", nums[i].a + nums[i].b);
        printf("\n");
        i = 0;
            
    }
    return 0;
}

so what should I write there while(empty line not reached) how do I make the program detect the empty line and go to the next test case?

Answer 1

Empty line has only one symbol.It is "new line" symbol. So you should look for two new lines symbols. If you work in non-binary mode with file you should look for \n\n symbols.