Thread: mode in 2-D array

Hi coders,,,
I have to find mean,mode and median of a 2-D array :
2 5 2 5 9 5 8 3 6 10
8 1 10 10 7 1 4 4 3 8
4 3 1 2 4 10 3 9 8 5
6 10 8 3 6 10 5 1 2 5
2 2 9 2 5 5 1 1 7 5
7 9 9 2 1 5 2 2 2 4
3 6 1 9 3 4 10 7 4 6
7 10 4 6 2 10 10 8 7 6
7 1 3 6 2 4 6 7 8 9
8 5 9 2 3 2 1 5 1 8

I coded for mean but stuck for mode.

Code:

// Assign4_Q2.cpp : Defines the entry point for the console application.
//


#include "stdafx.h"
#include<iostream>
#include<iomanip>
#include<conio.h>
using namespace std;


int i,j;


void calc_mean(int arr[10][10],int c)
{




   double sum=0,out=0;
   for(i=0;i<=9;i++)
		{   
			for(j=0;j<=9;j++)
			{
			
	            sum=sum+arr[i][j];
			}


		}
             
             out=sum/c;
			 cout<< "Mean is:" <<out<<endl;






}


void calc_mode(int arr[10][10],int freq[][]{


// stucked here
}


int main(int argc, _TCHAR* argv[])
{
	int count=0,mean;
	int arr[10][10]={2,5,2,5,9,5,8,3,6,10,8,1,10,10,7,1,4,4,3,8,4,3,1,2,4,10,3,9,8,5,6,10,8,3,6,10,5,1,2,5,2,2,9,2,5,5,1,1,7,5,7,9,9,2,1,5,2,2,2,4,3,6,1,9,3,4,10,7,4,6,7,10,4,6,2,10,10,8,7,6,7,1,3,6,2,4,6,7,8,9,8,5,9,2,3,2,1,5,1,8};
	int freq[10]={}; 
	for(i=0;i<=9;i++)
		{   
			for(j=0;j<=9;j++)
			{
			
				cout<<arr[i][j]<<",";


				count++;
			}


	    }	
	cout<<endl;
	cout<<"Array size is"<<count<<endl;
	calc_mean(arr,count);
	calc_mode(arr,freq);
  
	_getch();
	return 0;
}

I used the following for mode part(by following the technique of 1-D array) which didn't work,,

Code:

for(int i=0;j<=9;++i)
    {
      for(j=0;j<=9;j++)
	  {


      ++freq[arr[i][j]];


	  }
    }


  cout<<"Array value"<<setw(17)<<"Mode"<<endl;
  for(int k=0;k<=9;k++)
  {
  
  cout<<setw(6)<<k<<setw(17)<<freq[k]<<endl;
  
  }

Any Guidance will be Appreciated

Originally Posted by Salem

> I used the following for mode part(by following the technique of 1-D array) which didn't work,,
Presumably because the largest value in your array is 10.

Given your freq[10], this would be an array overrun.

The idea is sound, so long as your freq array is large enough.

BUT its not returning me the Mode despite the correct size of freq[]

Sample Output:
Rating Frequency
1 3
2 5
3 7
4 2
5 3

In mine case for 2-D its returning the frequency of '0' for each value of 'k'

to find the median you will need a nested loop and a counter.

Code:

#include <iostream>
#include <vector>

void mode(std::vector<int> v)
{
    int mode=0;
    int count=0;
    int result=0;
    
    
    std::sort(v.begin(), v.end());
    
    for (int i=0; i<v.size(); i++)
    {
        while (v[i]==v[i+1])
        {
            count++;
            i++;
        }
        if (count > result)
        {
            result=count;
            mode=v[i];
        }
        count=0;
    }
    
    std::cout<<"The mode is "<<mode<<"\n";
    
}

int main(int argc, const char * argv[])
{

   
    std::vector<int> numbers {10,10,10,10,44,33,4,4,4,2,5,3,6,4,1,3,7,7,3,4,7,4,7};
    
    mode(numbers);
    
    
    return 0;
}

I felt a little silly for not reading the other posts and just saying to use a loop and a counter. This is what I meant by that.