finding the mode in a vector

[kohlh]

I am working on a basic problem with vectors. How to find the mode. I have searched the internet and this forum and have not found a good answer, usually too confusing. I do not have any code written (for finding the mode) becuase I do not know where to start. I am doing this for homework and this is for extra points for creativity (I already made the mean, median and range). I have seen solutions that involve maps which seem to be designed for this task but could not understand the implementation given in that post specifically how to create the map and than assign the vector to the map. also I have thought the problem through and come to the idea that I could loop through the vector and check each element for equality to all other elements but this is sloppy and a work around. Here is the code so far for the rest of the program so that the answer given can be centered on the same style of implementation used.

#include<iostream>
#include<vector>
#include<algorithm>
#include<map>

using namespace std;

int main ()
{
	vector <double> HW3;    //declares a vector to store our data
	double num;             //declares a double to read data into vector
	double sum=0;   //declares a double to add the values of the vector elements

	cout<<"Enter in whole or decimal numbers, positive or negative."<<endl
		<<"When you are done entering data enter any letter to finish."<<endl;
	while(cin>>num)         
	{                         //allows user input of data, pushes that data 
		HW3.push_back(num);    //into the end of the vector untill cin fails
	}
	sort(HW3.begin(),HW3.end());//sorts vector elements into ascending order
	cout<<endl;
	for(double i=0;i<HW3.size();++i)
	{
		cout<<HW3[i]<<" ";           //displays sorted vector
	}
	cout<<endl<<"Total indices "<<HW3.size()<<endl;
	cout<<"The smallest value is "<<HW3.front()<<"."<<endl
	    <<"The largest value is "<<HW3.back()<<"."<<endl;  //displays the first and the last index in the vector                                                   

	for(int i=0;i<HW3.size();++i) //loops throught the vector
	{                                
		sum+=HW3[i];     //adds all the values of the elements in the vector and assignes it to sum
	}
	cout<<"The sum of all the values is "<<sum<<"."<<endl;         //displays the sum of the element values in the vector
	cout<<"The mean of all the values is "<<sum/HW3.size()<<"."<<endl;//displays the average of the element values
	if(HW3.size()%2==1)
	{
		int i=(HW3.size())/2;
		cout<<"The median is "<<HW3[i]<<endl;
	}
	else
	{
		double x=(HW3.size()/2.0);
		double y=((HW3.size()-1)/2.0);
		cout<<"The median is "<<((HW3[x]+HW3[y])/2.0)<<endl;
	}

	cout<<"The range is "<<abs(HW3.front()-HW3.back())<<endl;

	system("pause");
	return 0;
}

[cire]

You've sorted your vector, so it's fairly straightforward. Iterate through it while counting runs of the same value. The largest such run(s) will be your mode(s.)