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Join Date: May 2009

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MrNoob

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Find Biggest num

May 29th, 2009

I m trying to find the biggest number in the array but problem is that it keeps returning one

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
#include <stdio.h>
int FindBiggest(int *arr,int choice)
{
    int i;
	int num=0;
	for(i=0;arr[i]<=sizeof arr;i++) {
		    if(num<arr[i])
			    num=arr[i];
	}
	return num;
}    
int main(void)
{
    int arr[]={0,5,3};
    int result;
	result=FIND_NUM(arr,BIGGEST);
	printf("%d\n",result);
    getchar();
    return 0;
}
#include <stdio.h>
int FindBiggest(int *arr,int choice)
{
    int i;
	int num=0;
	for(i=0;arr[i]<=sizeof arr;i++) {
		    if(num<arr[i])
			    num=arr[i];
	}
	return num;
}    
int main(void)
{
    int arr[]={0,5,3};
    int result;
	result=FIND_NUM(arr,BIGGEST);
	printf("%d\n",result);
    getchar();
    return 0;
}

even though in my function i set the number to 0 first then after that we check with the if num<array[i] whish ofcourse it is now it we set the num to array[i] untill there no we found our biggest num i dunno its problem :s

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Join Date: Mar 2008

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William Hemsworth William Hemsworth is offline

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Re: Find Biggest num

May 29th, 2009

Is there any code you aren't posting? what is FIND_NUM and BIGGEST? You can't use sizeof to work out the length of an array passed to a pointer, instead you have to allow the caller to pass the length of the array as a parameter.

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Join Date: May 2009

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MrNoob

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Re: Find Biggest num

May 29th, 2009

yah i changed that i also changed in function the if better and still not working

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
#include <stdio.h>
int FindBiggest(int *arr)
{
    int i;
	int num=0;
	for(i=0;arr[i]<=3;i++) {
		    if(arr[i]>num)
			    num=arr[i];
	}
	return num;
}    
int main(void)
{
    int arr[]={0,5,3};
    int result;
	result=FindBiggest(arr);
	printf("%d\n",result);
    getchar();
    return 0;
}
#include <stdio.h>
int FindBiggest(int *arr)
{
    int i;
	int num=0;
	for(i=0;arr[i]<=3;i++) {
		    if(arr[i]>num)
			    num=arr[i];
	}
	return num;
}    
int main(void)
{
    int arr[]={0,5,3};
    int result;
	result=FindBiggest(arr);
	printf("%d\n",result);
    getchar();
    return 0;
}

now ofcourse 1st num is bigger than 0 whish should set num to 5 whats wrong now

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Join Date: Feb 2008

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jephthah

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Re: Find Biggest num

May 29th, 2009

your problem is here: for(i=0;arr[i]<=3;i++)

your index is 'i' yet your conditional is based on the value of 'arr' at the index 'i'

fix that.

.

Last edited by jephthah; May 29th, 2009 at 6:12 pm.

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Join Date: Mar 2008

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William Hemsworth William Hemsworth is offline

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Re: Find Biggest num

May 29th, 2009

Help with Code Tags

(Toggle Plain Text)

#include <stdio.h>

int FindBiggest(int *arr, int length)
{
  int i;
  int num = 0;

  for (i = 0; i < length; i++) {
    if ( arr[i] > num )
      num = arr[i];
  }

  return num;
}    

int main(void)
{
  int arr[] = {0, 5, 3};
  int length = sizeof(arr) / sizeof(arr[0]);
  int result;

  result = FindBiggest( arr, length );
  printf( "%d\n", result );

  getchar();
  return 0;
}

I highlighted the changes, also you were looping through too many elements in the array by using <=.

Last edited by William Hemsworth; May 29th, 2009 at 6:15 pm.

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Join Date: May 2009

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MrNoob

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Re: Find Biggest num

May 29th, 2009

i made it work now but what the diff between array[i] and just normal i?

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
#include <stdio.h>
int FindBiggest(int *arr)
{
    int i;
	int num=0;
	for(i=0;i<3;i++) {//used to be for(i=0;array[i<3;i++)
		    if(arr[i]>num)
			    num=arr[i];
	}
	return num;
}    
int main(void)
{
    int arr[]={0,5,3};
    int result;
	result=FindBiggest(arr);
	printf("%d\n",result);
    getchar();
    return 0;
}
#include <stdio.h>
int FindBiggest(int *arr)
{
    int i;
	int num=0;
	for(i=0;i<3;i++) {//used to be for(i=0;array[i<3;i++)
		    if(arr[i]>num)
			    num=arr[i];
	}
	return num;
}    
int main(void)
{
    int arr[]={0,5,3};
    int result;
	result=FindBiggest(arr);
	printf("%d\n",result);
    getchar();
    return 0;
}

in first line in the for loop ?

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Join Date: Mar 2008

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William Hemsworth William Hemsworth is offline

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Re: Find Biggest num

May 29th, 2009

>what the diff between array[i] and just normal i?
It's two completely different things, i is just an integer, array[i] is the element which is located at the index of i.

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Join Date: May 2009

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MrNoob

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Re: Find Biggest num

May 29th, 2009

thnaks man but i got one more question i made also a find biggest and smallest but it alawys get last element

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
#include <stdio.h>
#define BIGGEST 1
#define Smallest 0
int FindBiggest(int *arr,int choice)
{
    int i;
	int num=0;
	for(i=0;i<3;i++) {
		if(choice){//find BIGGEST NUM
		    if(arr[i]>num)
			    num=arr[i];
		}
		else
		{
			num=1000;
			if(arr[i]<num)
				num=arr[i];
		}
 
	}
	return num;
}    
int main(void)
{
    int arr[]={0,5,3};
    int result;
	result=FindBiggest(arr,Smallest);
	printf("%d\n",result);
    getchar();
    return 0;
}
#include <stdio.h>
#define BIGGEST 1
#define Smallest 0
int FindBiggest(int *arr,int choice)
{
    int i;
	int num=0;
	for(i=0;i<3;i++) {
		if(choice){//find BIGGEST NUM
		    if(arr[i]>num)
			    num=arr[i];
		}
		else
		{
			num=1000;
			if(arr[i]<num)
				num=arr[i];
		}

	}
	return num;
}    
int main(void)
{
    int arr[]={0,5,3};
    int result;
	result=FindBiggest(arr,Smallest);
	printf("%d\n",result);
    getchar();
    return 0;
}

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Join Date: Mar 2008

Posts: 1,434

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William Hemsworth William Hemsworth is offline

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Re: Find Biggest num

May 29th, 2009

If you are working out the biggest number, you have to start off with the smallest possible value and keep looking for a bigger value.

To find the smallest, you have to do the opposite. Start off with the biggest possible value, and keep looking for a smaller one.

Also it is more efficient to put the for loop inside the if block instead of the other way round, here is the corrected code:

 Help with Code Tags 
 C Syntax (Toggle Plain Text) 
#include <stdio.h>
#include <limits.h>
 
#define Biggest   1
#define Smallest  0
 
int FindBiggest(int *arr, int length, int choice)
{
  int i;
  int num = 0;
 
  if ( choice == Biggest ) {
    for (i = 0; i < length; i++) {
      if ( arr[i] > num ) { // Look for a bigger value
        num = arr[i];
      }
    }
  }
 
  else if ( choice == Smallest ) {
    num = INT_MAX; // Make it start off with the biggest possible value
    for (i = 0; i < length; i++) {
      if ( arr[i] < num ) { // Look for a smaller value
        num = arr[i];
      }
    }
  }
 
  return num;
}
 
int main(void)
{
  int arr[] = {2, 1, 3};
  int length = sizeof(arr) / sizeof(arr[0]); // Works out the length of arr
  int result;
 
  result = FindBiggest(arr, length, Smallest);
  printf("%d\n", result);
 
  getchar();
  return 0;
}
#include <stdio.h>
#include <limits.h>

#define Biggest   1
#define Smallest  0

int FindBiggest(int *arr, int length, int choice)
{
  int i;
  int num = 0;

  if ( choice == Biggest ) {
    for (i = 0; i < length; i++) {
      if ( arr[i] > num ) { // Look for a bigger value
        num = arr[i];
      }
    }
  }

  else if ( choice == Smallest ) {
    num = INT_MAX; // Make it start off with the biggest possible value
    for (i = 0; i < length; i++) {
      if ( arr[i] < num ) { // Look for a smaller value
        num = arr[i];
      }
    }
  }

  return num;
}

int main(void)
{
  int arr[] = {2, 1, 3};
  int length = sizeof(arr) / sizeof(arr[0]); // Works out the length of arr
  int result;

  result = FindBiggest(arr, length, Smallest);
  printf("%d\n", result);

  getchar();
  return 0;
}

Last edited by William Hemsworth; May 29th, 2009 at 6:30 pm.

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jephthah

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Re: Find Biggest num

#10

May 29th, 2009

•

i made also a find biggest and smallest but it alawys get last element

because for the smallest, you set num=1000 every single time you go through the loop. arr[i] will always be less than 1000 each time, so it stores it in num, each time.

EDIT: i see William already re-wrote your code for you. consider yourself (un)lucky, because i would have made you fix it yourself.

Last edited by jephthah; May 29th, 2009 at 6:34 pm.