Why reading '+' and '-' not work in Linux?

Question

I have this fragment of code that reads arithmetic expressions like 1 + 2 * 3 into integers and characters:

int main() {
    int d, flag = 0;
           


        

Answer 1

'+2' was scanned to 'd' because of scanf("%d", &d)). You can try with '1-2' and see that '-' also can't display.