print it only if it is not a duplicate [modified][solved]

Omegaclass

what is wrong with my code it's kicking me in the head right now and if a kind soul could help me out i would be very grateful, thanks. here is the goal: Use a one dimensional array to solve the following problem. Read in 20 numbers, each of which is between 10 and 100, inclusive. As each number is read, print it only if it is not a duplicate of a number already read. Provide for the “worst case” in which all 20 numbers are different. Use the smallest possible array to solve this problem.Well,

#include <iostream>
#include <iomanip>
#include <ctime>
#include <cstdlib>
#include <limits>
const int x = 20;
using namespace std;

int main()

{

              int i = 0;
              int toss = 0;
              int count=0;
              int population\[20\];
              int num=0;
              bool duplicate = false;
              

	      while(1)
          { 
              			   
              for (int j = 0; j < x; j++)    // test for duplicate random num
              {
                 
                  srand(time(NULL));
                  num = rand()%90+11;
                  
                if (num == population\[j\])
		    
                {
				duplicate = true;
		        toss++;
			    //break; 
                }  // exit the loop if true 
	        
            
                if (!duplicate)
                {   // if not duplicate
		          
                 population\[j\] = num;  // fill the dynamic array
                 count++;
                 } 
              }

		   
               
               for (int ii = 0; ii <= count; ii++)
               {
               cout << population\[ii\]<<" ";
               }
               cin.clear();
               cin.get();
               }
               }

Chris Losinger

i think you need to re-think the problem. here's a hint: the population array is going to start out with 0 items in it. after the first number read, it will have one item in it. after the second, it can have one or two. after the third, one, two or three. you need to keep track. here's another hint: you're going to have two loops: one going from 0-19, to read the numbers, and another, inside the first, going from 0-N, where N is the number of items you've read and stored.

image processing toolkits | batch image processing

Omegaclass

I turned in my assignment, but it wasn't right, so i lost some points, i was wondering if you could give an example on how to do this the right way? i apologize for asking, but my professor is very hard to understand due to the fact he is not a native speaker of English so mush of what i do know is self taught.

Chris Losinger

roughly, and in pseudo-code:

int storage[20]
int numStored = 0

// loop over the 20 numbers you need to read
loop 0 to 20, i

// read a value
int newVal = read_a_value;

// see if you've already read that value
bFound = false

// loop over stored numbers
loop 0 to numStored
// if it's in the storage array, set the bFound flag
if storage[i] = newVal
bFound = true
break
.

// if you didn't find it, store it
if not bFound and numStored < 20
storage[numStored] = newVal
numStored = numStored + 1
.

image processing toolkits | batch image processing

Omegaclass

Thanks Chris for taking your valuable time and helping me out, i really want to learn c++ and plan to take OOP next semester. so far my grades are in the low 90's and don't want to blow it towards the end of this semester.

dose all this belong in the same for loop? i am not sure what you are
saying in "read a value" could this be what you are
saying, "newVal = read_a_value[i];" or is
this it "newVal = rand()%91+10;"

how do i implement "see if you've already read that number" if after the
2nd number i will need to see if the previous number has been read and
chick if it's a duplicate. and each time a new number is generated it
must be checked to the others to see if its already there. i am having
a hard time visualizing the logic and i really do appreciate your time
to help me with this.

for loop 0 to 20, i
{

// read a value
int newVal = read_a_value;

// see if you've already read that value
bFound = false

// loop over stored numbers
loop 0 to numStored
// if it's in the storage array, set the bFound flag
if storage[i] = newVal
bFound = true
break

}

Chris Losinger

Omegaclass wrote:

dose all this belong in the same for loop?

you'll have two loops. one inside the other.

Omegaclass wrote:

i am not sure what you are saying in "read a value"

that's where you get the next input. your original msg says "Read in 20 numbers, each of which is between 10 and 100, inclusive." so, if the test data is coming from a file, you'll need to open that file then read each number one at a time. or, if it's coming from the keyboard, or from stdin, or cin, etc.. rand() will work for testing, i guess. but that seems like a strange assignment. i know when i would get assignment like this, the instructor would have a set of data files that he'd send into the program, to make sure the app was doing what it was supposed to on known input.

Omegaclass wrote:

how do i implement "see if you've already read that number" if after the 2nd number i will need to see if the previous number has been read and chick if it's a duplicate.

the previous number will be in the storage array - if it was duplicate, it was already there; if it was a new one, then you will have added it. so, you just need to loop through the items in the storage array and compare each one to the new value.

image processing toolkits | batch image processing

Omegaclass

Thank you Chris i get it now. i appreciate your time. this road i am on learning C++ has not been easy, but it is interesting.