program skipping lines

[cecnik]

 
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
 
struct kart
{
       float x;
       float y;
};
 
struct polar
{
       float r;
       float fi;
};
int main()
{
 
    struct kart T1_kart;
    struct kart T2_kart;
    struct polar T1_polar;
    struct polar T2_polar;
    int a, b;
    float kot, c, d;
 
 
printf("Ce zelite pretvarjati iz iz kartezicnih koordinat v polarne vnesite k, sicer vnesite p.\n");
scanf("%c", &a);
 
switch(a)
{
         case 'p':{
              printf("Vnesite dolzino vektorja!\n");
              scanf("%f", &T1_polar.r);
              printf("Vnesite kot!(kasneje boste izbrali enoto - radiani/stopinje)\n");
              scanf("%f", &kot);
              printf("Vnesite s za stopinje ali r za radiane.\n");
              scanf("%c", &b);
              switch(b)
              {
              case 's':{
                   T1_polar.fi=kot/57.2957795131;
                   break;
                   }
              case 'r':{
                   T1_polar.fi=kot;
                   break;
                   }
              default:{
              printf("Znova zazenite program in vnesite veljavno vrednost\n");
             system("pause");
             return 0;
             }
             }
             T1_kart.x=T1_polar.r*cos(T1_polar.fi);
             T1_kart.y=T1_polar.r*sin(T1_polar.fi);
             printf("x = %f, y = %f, r = %f, fi = %f rad\n",T1_kart.x,T1_kart.y,T1_polar.r,T1_polar.fi);
             break;
 
             }
         case 'k':{
              printf("Vnesite koordinati vektorja!\n\nx= ");
              scanf("%f", &T2_kart.x);
              printf("y= ");
              scanf("%f", &T2_kart.y);
              c=((T2_kart.x*T2_kart.x)+(T2_kart.y*T2_kart.y));
              d=T2_kart.y/T2_kart.x;
              T2_polar.r=sqrt(c);
              T2_polar.fi=atan(d);
              printf("r = %f, fi = %f, x = %f, y = %f\n",T2_polar.r,T2_polar.fi,T2_kart.x,T2_kart.y);
              break;
              }
         default:{
         printf("Znova zazenite program in vnesite veljavno vrednost\n");
             system("pause");
             return 0;
             }
 
 
 
 
}
 
    system("PAUSE");    
    return 0;
}
 

So here is the code I wrote. It works perfectli when your first input is "k" but if you input "p" it works till the line

printf("Vnesite s za stopinje ali r za radiane.\n");

after that it skips everything too the default statement (the default statement in switch(b)). Any ideas?

p.s.

It's a school assignment so I didn't translate the printf stuff, basicly those are instructions to put in information necessary to convert polar coordinates (case 'p') to cartesian and the other way around (case 'k').

[weaknessforcats]

Firstly, you are using scanf into an int. That means you use the %d format specifier. 'k' and 'p' are valid int values. The int is just bogger than the char but both ae integer variables.

Second, when you enter a 'p' the case for 'p' processes and does a return. That's the end of your program since that is a return from main().

Your switch structure should look like:

int a = 0;
    int b = 0;
 
    switch (a) 
    {
    case 'p':
    {
                switch (b)
                {
                case 's':
                {
                            //...etc...
                                break;    // exit switch (b)
                }
                } //end of switch (b)
        break; //exit switch (a)
    }
 
    }    
 

Those return 0 statements were put in because the switch statements were not coded correctly, so the program did one case and quit main().

[divideby0]

check "b" to see if it's picking up the new line char instead of your expected input; mixing data types with scanf can be a nuisance.