Thread: stupid computer class...need help please

Originally Posted by TheBigH

Okay, so that's three floats and (I think) an int. Your fscanf needs to read all those in; currently it's only reading in balloonLaunchAngle.

So how would I put that in syntax?

Originally Posted by TheBigH

Leave the quotes in the #define, and go with Strahd's second suggestion. See if that works.

Alright, that gives me my output without the error message so I'm getting somewhere!
There is a picture of what the output looks like in a picture in one of the above posts

Originally Posted by tayexdrums

So how would I put that in syntax?

If you would look up the scanf function, you could find out. http://linux.die.net/man/3/scanf

Hint:

Code:

float a, b, c;
int i;
fscanf(fp, "%f %f %f %i", &a, &b, &c, &d);

that's what I thought it would look like. I guess what I'm asking is how to read in those values with the compiler KNOWING that the first column is the balloonLaunchAngle, second column balloonLaunchVelocity, third throwersHeight, fourth balloonDiameter

Originally Posted by tayexdrums

that's what I thought it would look like. I guess what I'm asking is how to read in those values with the compiler KNOWING that the first column is the balloonLaunchAngle, second column balloonLaunchVelocity, third throwersHeight, fourth balloonDiameter

Did actually read how the (f)scanf function works? If you did, then you would know that the first value is stored in variable a, second value in variable b and so on. So what do you want? You want to store the first value into balloonLaunchVelocity (or whichever was the first column in the file) etc. So just change a, b, c and d to your corresponding variable names.

Right I know that...so the first value will be stored in the variable balloonLaunchAngle, the second value will be stored in the variable balloonLaunchVelocity, the third value will be stored in the variable throwersHeight, the fourth value will be stored in the variable balloonDaimeter. My question is how do you tell it to repeat this? such as when you get to 5, 6 , 7, and 8

Right I know that...so the first value will be stored in the variable balloonLaunchAngle, the second value will be stored in the variable balloonLaunchVelocity, the third value will be stored in the variable throwersHeight, the fourth value will be stored in the variable balloonDaimeter. My question is how do you tell it to repeat this? such as when you get to 5, 6 , 7, and 8

Originally Posted by tayexdrums

Right I know that...so the first value will be stored in the variable balloonLaunchAngle, the second value will be stored in the variable balloonLaunchVelocity, the third value will be stored in the variable throwersHeight, the fourth value will be stored in the variable balloonDaimeter. My question is how do you tell it to repeat this? such as when you get to 5, 6 , 7, and 8

You are already doing something like that in your code, you have:

Code:

while((fscanf(balloonValues,"%f",&poolWater))==1)
{
    ...
}

The return value from fscanf is the number if items read, so you could change the value it compares with to either 4 to make sure you always read the four values you need, or EOF to check if it has read to the End Of File. Perhaps even throw in some error handling there in case the file data is corrupted :-)

Code:

while ((fscanf(balloonValues, "%f %f %f %i", &balloonLaunchAngle, &balloonLaunchVelocity, &throwersHeight, &balloonDaimeter)) == 4)

or

Code:

while ((fscanf(balloonValues, "%f %f %f %i", &balloonLaunchAngle, &balloonLaunchVelocity, &throwersHeight, &balloonDaimeter)) != EOF)

Okay, I see, that makes sense=]
I'm still getting wrong output though=[

Originally Posted by tayexdrums

Okay, I see, that makes sense=]
I'm still getting wrong output though=[

Can you re-post your new code, along with the generated output and your expected output?

Code:

#include<stdio.h>            //standard library definitions
#include<stdlib.h>
#include<math.h>            //math definitions
#define BAL_HEIGHT 12    //balcony height in feet
#define G  32               //gravitational acceleration in ft/s2
#define PI 3.14159
#define POOL_CENTER 35  //distance to the center of pool
#define MIN_THETA 5        //minimum balloon launch angle in degrees
#define MIN_VEL 1            //minimum balloon launch velocity in ft/sec
#define MIN_THR_HT 4.5    //minimum height of thrower in feet
#define MAX_THETA 85        //maximum balloon launch angle in degrees
#define MAX_VEL 30        //maximum balloon launch velocity in ft/sec
#define MAX_THR_HT 7.0    //maximum height of thrower in feet
#define MIN_DIAM 3        //minimum diameter of balloon in inches
#define MAX_DIAM 9        //maximum diameter of balloon in inches
#define CAPACITY 7        //pool capacity in gallons
#define FILENAME "balloonValues.txt"    //input data file

   int main()
   {
      double balloonLaunchAngle;                    //input: angle in degrees
      double balloonLaunchVelocity;                //input: launch velocity in ft/sec
      double throwersHeight;                        //input: user's height plus balcony height in feet
      double distanceTraveled;                    //output: distance the balloon traveled in feet
      double part1, part2, part3;                //distance formula: partial result holders
      int balloonDiam;                               //ballon diameter in inches
      double balloonWater;                            //amount of water in balloon in gallons
      double poolWater;                            //amount of water in pool in gallons
      int balloonNumThrown;                        //number of balloons "thrown"
      int balloonNumHit;                            //number of balloons that "hit" the pool
       
      FILE *balloonValues;
      balloonValues=fopen(FILENAME,"r");
      if(balloonValues==NULL)
      {
         printf("Error opening input file.");
      }
      else
      {
         poolWater=0;
         balloonNumThrown=0;
         balloonNumHit=0;
         srand(time(NULL));
         while((fscanf(balloonValues,"%f %f %f %d", &balloonLaunchAngle,  &balloonLaunchVelocity,   &throwersHeight, &balloonDiam))!=EOF)
         {
            balloonNumThrown++;
             
         
            switch(balloonDiam)
            {
               case 3: balloonWater=0.1;
                  break;
               case 4: balloonWater=0.2;
                  break;
               case 5: balloonWater=0.3;
                  break;
               case 6: balloonWater=0.55;
                  break;
               case 7: balloonWater=0.8;
                  break;
               case 8: balloonWater=1.25;
                  break;
               case 9: balloonWater=1.7;
                  break;
            }
            
            part1=(balloonLaunchVelocity*cos(balloonLaunchAngle*PI/180.0))/G;
            part2=balloonLaunchVelocity*sin(balloonLaunchAngle*PI/180.0);
            part3=2*G*(throwersHeight+BAL_HEIGHT);
            distanceTraveled=part1*(part2+(sqrt(pow(part2,2)+part3)));
             
            if(distanceTraveled>POOL_CENTER-1 && distanceTraveled<POOL_CENTER+1)
            {
               poolWater=poolWater+balloonWater;
               balloonNumHit++;
            }
            if(poolWater<CAPACITY)
               balloonNumThrown;
         }
        fclose(balloonValues); 
      }
       
       printf("%f\n %f \n%f \n%d\n", &balloonLaunchAngle,  &balloonLaunchVelocity,  
         &throwersHeight, &balloonDiam); //threw that in there just to check that I am getting values
      printf("%d balloons hit the pool.\n", balloonNumHit);
      printf("%d balloons were thrown.\n", balloonNumThrown);
      printf("%.2f %% balloons hit the pool.\n", (double)balloonNumHit/balloonNumThrown*100);
      printf("The pool was full after balloon #%f", poolWater);
      //fclose(balloonValues);
      return(0);

the output should look like this...but in the directions it says that everyone will probably have different answer
8 balloons hit the pool.
275 balloons were thrown.
2.91% balloons hit the pool.
The pool was full after balloon #218.
3.00 gallons of water spilled over the edge of the pool. ( I haven't done this one yet)

Originally Posted by tayexdrums

Code:

 printf("%f\n %f \n%f \n%d\n", &balloonLaunchAngle,  &balloonLaunchVelocity, &throwersHeight, &balloonDiam);

You have to remove the &'s from that line. As it is now, it tries to print the memory address of the variables instead of the actual values.

oops, okay, now here's what I get everytime I run the program...