Little array issue

[Ninja]

Hey guys!.Ok so i was working on this assignment.Basically here is what it is.An array holds marks entered by the user.We have to assume that the user wont enter more than 40 values. So i wrote the code for it (sorry for any sloppyness or errors, still working on it lol).The user can terminate the program by entering -1..but when you go to print the array (say you enter 4 marks) it prints all 40 instead of just the 4 entered.Here is the code...can anyone tell me what i'm doing wrong here cause i can't figure out.Thanks in advance!

code:

#include <stdio.h> #include <stdlib.h> #define MAX 40 void printArray(float marks[],int arr_size); float calcMedian(float marks[ ], int arr_size); void sortArray(float marks[], int array_size); isValid(float score); enum bool {true,false}; float marks_valid[MAX]; main () {      int i,choice,valid = 0,invalid = 0;         float marks,sum = 0,mean = 0,median,min = 0,max = 0;                     for (i=0; i < MAX; i++)      {                  printf("Enter mark:");         scanf("%e",&marks);         fflush(stdin);         if (marks == -1)         {            break;         }                else if (isValid(marks)== true)        {            valid++;            marks_valid[i] = marks;               min = (marks_valid[i] < min)? marks_valid[i]: min;            max = (marks_valid[i] > max)? marks_valid[i]: max;            sum+= marks_valid[i];                   }                    else         {           invalid++;         }      }                   system("cls");      mean = sum/valid;      printf("Valid: %d\n",valid);       printf("Invalid: %d\n",invalid);               getch();      system("cls");      sortArray(marks_valid, MAX);      printf("**************MAIN MENU**************\n");      printf("1.Print test scores\n");      printf("2.Print stats\n");      printf("**************MAIN MENU**************\n");      scanf("%d",&choice);            if(choice == 1)      {         system("cls");         printArray(marks_valid,MAX);                getch();      }            else if (choice == 2)      {                printf("Sum: %.2lf\n",sum);         printf("Average: %.2lf\n",mean);         printf("Min score: %.2lf\n",min);         printf("Max score: %.2lf\n",max);         getch();       }       } void printArray(float marks[],int marks_size) {      int i;           sortArray(marks_valid, MAX);           for (i = 0; i < MAX; i++)      {         printf("Test Scores entered: %.2lf \n",marks[i]);              }    } isValid(float score) {       if (score >= 0 && score <= 100)       {         printf("Valid\n");                return true;       }             else       {           printf("Invalid!\n");              return false;       } } void sortArray(float marks[], int array_size) {   int i, j;   float index;   for (i=1; i < array_size; i++)   {     index = marks[i];     j = i;     while ((j > 0) && (marks[j-1] > index))     {       marks[j] = marks[j-1];       j = j - 1;     }     marks[j] = index;   } }

[HeavenAgain]

code:

for (i = 0; i < MAX; i++)      {         printf("test Scores entered: %.2lf \n",marks[i]);              }

instead of from 1 to 40, you can add a counter for everytime they enetered a number, and go from there

code:

for (int i = 0 ; i < counter; i++)     {         printf("test Scores entered: %.2lf \n",marks[i]);     }

[Saad]

code:

void printArray(float marks[],int marks_size) {      int i;           sortArray(marks_valid, MAX);           for (i = 0; i < MAX; i++)      {         printf("test Scores entered: %.2lf \n",marks[i]);              }    }

You use MAX as your number of scores entered when printing them out
Hoever you should be marks_size that you pass to the printArray function.


Saad

[Ninja]

HeavenAgain @ Thu Mar 13, 2008 6:00 pm wrote:

code:

for (i = 0; i < MAX; i++)      {         printf(" Scores entered: %.2lf \n",marks[i]);              }

instead of from 1 to 40, you can add a counter for everytime they enetered a number, and go from there

code:

for (int i = 0 ; i < counter; i++)     {         printf(" Scores entered: %.2lf \n",marks[i]);     }

Hmmm...but the array is still initialized with a size of 40..any way to change the size of the array by counting how many valid numbers the user enters.Ahhh..i wish i could use C++ for this class, vectors make life easier lol.

[HeavenAgain]

make your valid variable global, and then you'll have

code:

for (int i = 0 ; i < valid; i++)     {         printf(" Scores entered: %.2lf \n",marks[i]);     }

you dont change the size or anything, just keeping track of how many valid are entered, and use that number to print from 0 - numberValid-1 (0 base index), get what i mean?

eg. your array size is 40, currently is empty with 0s
now i entered 1, 2, 3, -1, 4, 5
i entered 6 numbers, valid now is 5, and i only stored 1, 2, 3, 4, 5 (with respect to their index)
and now i want to print that number, so we use valid, which is 5, and print.

edit: as Saad pointed out, your parameter, you passed in "printArray(marks_valid,MAX); " MAX, but instead maybe you should pass in valid, and then you dont have to make valid a global variable.

[Ninja]

OMG haha..so get this.I did what saad said, but i typed it wrong and it gave me an error..so out of frustration i was like to hell with this! lol. But i got it working now, actually i just thought of what u said and it works , and then i read your reply haha.Thanks a lot guys!!

Now i can go email this to my class cause they have no clue what to do lol.

[A.J]

As HeavenAgain said, you could use a counter