String Selection Sort in C++

问题:

Need some help with string for my selection sort. Here's what I have so far.

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

//Constant globals
const int NUM_NAMES = 20;

//Function protoypes
void selectionSort(string [], int);
void showArray(const string [] , int);

int main()
{
string names[NUM_NAMES] = {"Collins, Bill", "Smith, Bart", "Allet, Jim",
                           "Griffin, Jim", "Stamey, Marty", "Rose, Geri", 
                           "Taylor, Terri", "Johnson, Jill", 
                           "Aliison, Jeff", "Weaver, Jim", "Pore, Bob", 
                           "Rutherford, Greg", "Javens, Renee", 
                           "Harrison, Rose", "Setzer, Cathy", 
                           "Pike, Gordon", "Holland, Beth"};

char again; //Hold y to repeat

do
{
    //Show array
    cout << "The unsorted values are\n";
    showArray(names, NUM_NAMES);

    //Sort array
    selectionSort(names, NUM_NAMES);

    //Display sorted array
    cout << "The sorted values are\n";
    showArray(names, NUM_NAMES);

    //Run program again?
    cout << "Would you like to run the program again? (Y/N): ";
    cin >> again;
}while(again == 'y' || again == 'Y');
return 0;
}

Updated my code and it works perfect. Changed minValue from int to string.

void selectionSort(string array[], int NUM_NAMES)
{
int startScan, minIndex;
string minValue;

for(startScan = 0; startScan < (NUM_NAMES -1); startScan++)
{
    minIndex = startScan;
    minValue = array[startScan];
    for(int index = startScan +1; index < NUM_NAMES; index++)
    {
        if (array[index] < minValue)
        {
            minValue = array[index];
            minIndex = index;
        }
    }
    array[minIndex] = array[startScan];
    array[startScan] = minValue;
}
}

If someone can help me out here that would be greatly appreciated.

回答1:

minValue = array[startScan];

You are assigning a string to an int. Make the type of minValue as string. Then it should work.

回答2:

c++ and stl makes selection sort much simpler and elegant (strings or integer whatever)

vector<string> v={"chandler","joey","phoebe","ross","rachel","monica"};
for(auto i=v.begin();i!=v.end();i++)
iter_swap(i, min_element(i,v.end()));
for(auto&x : v) cout<<x<<" ";//printing the sorted vector

incase you are not using c++14, simply change the auto to the vector iterator.

回答3:

This might help:

import java.util.Arrays;

public class StringSort {
    public static void main(String[] args){

        final int nu_names = 20;
        String names[ ] = new   String[nu_names];
         names = new String[]{"Collins, Bill", "Smith, Bert", "Allen, Jim",
                                 "Griffin, Jim", "Stamey, Marty", "Rose, Geri",
                                 "Taylor, Terri", "Johnson, Jim",
                                  "Allison, Jeff", "Looney, joe", "Wolfe, Bill",
                                  "James, Jean", "Weaver, Jim", "Pore, Bob",
                                   "Rutherford, Greg", " Javens, Renee",
                                  "Herrison, Rose", "Setzer, Cathy",
                                   "Pike, Gordon", "Holland, Beth"};

         sort(names);
         System.out.print(Arrays.toString(names));// print names

    }
    //sort method
    public static void sort(String[] names){
        String currentName = "";
        int currenIndex = 0;
        for(int i = 0; i < names.length - 1; i++){
            currentName = names[i];
            currenIndex = i;
            for(int j = i + 1; j < names.length; j++){
                if(currentName.compareTo(names[j]) > 0) {
                    currentName = names[j];
                    currenIndex = j;
                }
            }
             swap(names, i,currenIndex );
        }
    }
     //Swap when necessary
    public static void swap(String[] names, int a, int b){
        String temp = names[a];
        names[a] = names[b];
        names[b] = temp;
    }
}