按字母顺序打印存储在字符数组中的信息

在一个文件中，我将不同人的姓名和地址存储在一个数组中。此数组的类型为 Person(结构(，由两个字符数组组成，一个用于姓名和姓氏，一个用于地址。我已经设法在屏幕上显示人物，但现在我必须按照姓氏的字母顺序排列他们。

在下面显示的代码中，我首先找到了姓氏的第一个元素的索引，并将它们保存在一个数组中。然后我创建了另一个数组，其中存储了姓氏的第一个字符。之后，我做了一个 for 循环，并将数组上的第一个字母与 if 语句进行了比较，并对气泡进行了排序。不幸的是，在我打印了人们的名字/姓氏和地址后，它们没有正确排序。

#include<fstream>
#include<iostream>
#include<string>
#include<iomanip>
#include<math.h>
#include<fstream>
#include<iostream>
#include<string>
#include<iomanip>
#include<math.h>
#include<time.h>
#include<string.h>
#include<stdio.h>
#include<stdlib.h>
using namespace std;
struct Person {
char name[30];
char address[50];
};
typedef struct Person Person;
//to find in only for one person
//only for one individual
int getSurnameIndex(Person people )
{
int count=0; //to keep track in what character we are
int len=strlen(people.name);
int surnameIndex=0;
for(int i=0;i<len;i++)
{
if(people.name[i]== ' ')
{
surnameIndex=count+1; //surname comes one character after the space
}
count++;
}
return(surnameIndex);
}
int main()
{
ifstream a1("a1.txt");
Person people[20];
int numPeople=0;
int i=0; //we can use numPeople because is the same thing but only because we are used with for(int i=0;...) will put i on there
while(!a1.eof())
{
a1.getline(people[i].name, 30);
a1.getline(people[i].address, 50);
a1.get();
i++;
numPeople++;
}
cout<<"The number of people in the file is "<<numPeople<<"."<<endl<<endl;
for(int i=0;i<numPeople;i++)
{
cout<<people[i].name<<endl<<people[i].address<<endl<<endl;
}
//now how to print the letter of surname

int surnameIndex=getSurnameIndex(people[0]);
cout<<"The index for the first person is: "<< surnameIndex<<endl;
//now to make if for all the people and store the indexes on an array
int surnameIndexes[20];
cout<<"Here are the indexes of of the people stored in the array:" <<endl;
for(int i=0;i<numPeople;i++)
{
surnameIndexes[i]=getSurnameIndex(people[i]);
cout<<surnameIndexes[i]<<endl;
}
// here we store the first letters of surnames into a char array
char surnameLetter[20];
for(int i=0;i<numPeople;i++)
{
surnameLetter[i]=people[i].name[surnameIndexes[i]];
}
cout<<endl<<endl;
for(int i=0;i<numPeople;i++)
{
cout<<surnameLetter[i]<<endl;
}
//now comparing the letters and bubble bobble sort
//this is not sorting properly
for(int i=1;i<6;i++)
{
for(int j=1;j<6;j++)
{
if(surnameLetter[i-1] > surnameLetter[i])
{
Person temp;
temp=people[i-1];
people[i-1]=people[i];
people[i]=temp;
char tempChar;
tempChar=surnameLetter[i-1];
surnameLetter[i-1]=surnameLetter[i];
surnameLetter[i]=tempChar;
}
}
}

for(int i=0;i<numPeople;i++)
{
cout<<people[i].name<<endl<<people[i].address<<endl<<endl;
}
return 0;
}