按字母顺序排序数组c ++

Question

编写一个程序以按字母顺序对名称进行排序和显示（使用选择排序）。程序提示用户输入要搜索的名称（使用二进制搜索）。该程序还对名字和姓氏的第一个字符的大写进行了更正。

我只能弄清楚如何使用算法库，但我不允许使用它。

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


int main() {
    const int SIZE = 20;
char temp;
int i, j;
bool madeAswap;
char arr[SIZE][SIZE] = { "Collins, Bill", "Smith, Bart", "Michalski, Joe",
    "Griffin, Jim","Sanchez, Manny", "Rubin, Sarah", "Taylor, Tyrone",
    "Johnson, Jill","Allison, Jeff", "Moreno, Juan", "Wolfe, Bill",
    "Whitman, Jean","Moretti, Bella", "Wu, Hong", "Patel, Renee",
    "Harrison, Rose","Smith, Cathy", "Conroy, Pat", "Kelly, Sean", "Holland, Beth" };
do {
    madeAswap = false;
    for (i = 1; i < SIZE; i++)
    {
        for (j = 1; j < SIZE; j++)
        {
            if (strcmp(arr[j - 1], arr[j]) > 0)
            {
                temp = arr[i][i];
                arr[i][i] = arr[i + 1][i + 1];
                arr[i + 1][i + 1] = temp;
                madeAswap = true;
            }
        }
    }
    }while (madeAswap);
for (int j = 0; j < SIZE; j++) {
    cout << arr[j][j] << endl;
}
system("pause");
return 0;

}

Answer 1

首先，这不是任何排序算法，而是接近冒泡排序，一种耗时的算法。您再次以随机方式处理字符而不是字符串。 看看我所做的这个修改，它只会对你的数组进行排序

#include <iostream>
#include <string>
using namespace std;

int main() {
    const int SIZE = 20;
    string temp;
    int i, j;
    string arr[SIZE] = { "Collins, Bill", "Smith, Bart", "Michalski, Joe",
        "Griffin, Jim","Sanchez, Manny", "Rubin, Sarah", "Taylor, Tyrone",
        "Johnson, Jill","Allison, Jeff", "Moreno, Juan", "Wolfe, Bill",
        "Whitman, Jean","Moretti, Bella", "Wu, Hong", "Patel, Renee",
        "Harrison, Rose","Smith, Cathy", "Conroy, Pat", "Kelly, Sean", "Holland, Beth" };
    for (i = 1; i < SIZE; i++)
    {
        for (j = 1; j < SIZE; j++)
        {
            if ( arr[j-1] > arr[j])
            {
               temp = arr[j-1];
               arr[j-1] = arr[j];
               arr[j] = temp;
            }
        }
    }
    for (int j = 0; j < SIZE; j++) {
        cout << arr[j] << endl;
    }
    system("pause");
    return 0;
}

Answer 2

您说您需要使用“选择排序”，但您使用的是“冒泡排序”。我在两个循环（for）和字符串交换（move）上修改了你的程序。

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

int main() {
    const int SIZE = 20;
    string temp;
    int i, j;
    string arr[SIZE] = { "Collins, Bill", "Smith, Bart", "Michalski, Joe",
        "Griffin, Jim","Sanchez, Manny", "Rubin, Sarah", "Taylor, Tyrone",
        "Johnson, Jill","Allison, Jeff", "Moreno, Juan", "Wolfe, Bill",
        "Whitman, Jean","Moretti, Bella", "Wu, Hong", "Patel, Renee",
        "Harrison, Rose","Smith, Cathy", "Conroy, Pat", "Kelly, Sean", "Holland, Beth" };
    for (i = 0; i < (SIZE - 1); i++)
    {
        for (j = (i+1); j < SIZE; j++)
        {
            if ( arr[i] > arr[j])
            {
               temp = arr[i];
               arr[i] = arr[j];
               arr[j] = temp;
            }
        }
    }
    for (int j = 0; j < SIZE; j++) {
        cout << arr[j] << endl;
    }
    system("pause");
    return 0;
}

真正的“选择排序”具有比较复杂度 O (n ^ 2) 和移动复杂度 O (n)。我认为正确的实现方式应该是这样的：

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

int main() {
    const int SIZE = 20;
    string temp;
    int i, j;
    string arr[SIZE] = { "Collins, Bill", "Smith, Bart", "Michalski, Joe",
        "Griffin, Jim","Sanchez, Manny", "Rubin, Sarah", "Taylor, Tyrone",
        "Johnson, Jill","Allison, Jeff", "Moreno, Juan", "Wolfe, Bill",
        "Whitman, Jean","Moretti, Bella", "Wu, Hong", "Patel, Renee",
        "Harrison, Rose","Smith, Cathy", "Conroy, Pat", "Kelly, Sean", "Holland, Beth" };
    for (i = 0; i < (SIZE - 1); i++)
    {
        int k = i;
        for (j = (i+1); j < SIZE; j++)
        {
            if ( arr[k] > arr[j])
            {
               k = j;
            }
        }
        if (i != k) {
            temp = arr[i];
            arr[i] = arr[k];
            arr[k] = temp;
        }
    }
    for (int j = 0; j < SIZE; j++) {
        cout << arr[j] << endl;
    }
    system("pause");
    return 0;
}

解释代码：String 是一个包含字符数组的 C++ 类。语句“string arr [SIZE]”是一个大小为 SIZE 的字符串数组。您可以参考'http://www.cplusplus.com/reference/string/string/'处的字符串类。

您的代码中的另一个问题与排序有关。 “选择排序”通过将一个元素与后续元素进行比较来对列表进行排序，所以你的第二个循环是错误的，它应该是：'for (j = (i + 1); j

最后，你只需要在你完成整个j for之后进行交换（移动）。