Question

I need to read an input file like :

1
19 20 41 23
2
41 52 43
3
90 91 941
4
512
5

6
51 61

Each odd line is an integer. Each even line is unknown number of integers.

It is very easy in C++

while( cin >> k ){
............
}

I’m not so used to C, so I couldnt make it in C. Any ways to do it?

Answer 1

The way I would do it is to break it down into two operations: read a line, then read the integers in that line. Here is a lazy implementation using the standard C library:

char line[1024], *p, *e;
long v;
while (fgets(line, sizeof(line), stdin)) {
    p = line;
    for (p = line; ; p = e) {
        v = strtol(p, &e, 10);
        if (p == e)
            break;
        // process v here
    }
}