Help with Selecting Sort of Structures

[linuxjr]

I have two structures
struct StudentRec {
char name[25]; // Name of student
float average; // Student's average
};

struct Roster {
StudentRec student[100];
int numStudent;
};

I have this function that I'm trying to sort the names in order:

void sort(Roster& r)
{
for (int k =0; k < r.numStudent - 1; k++){
int next = k;
for(int j = k+1; j < r.numStudent; j++)
if(j < next)
next = j;

StudentRec temp; //Swapping buffer
strcpy(temp.name, r.student[next].name);
strcpy(r.student[next].name,r.student[k].name);
strcpy(r.student[k].name,temp.name);
}
}

I know it will fail at the if statement and I have tried next < j but that will only sort one or two. Any suggestions will be greatly appreciated. Have a nice night.

 

[ArkM]

You must compare r.student[j].name with r.compare[k].name (by strcmp from <cstring>)! Now you always have j < next because (k+1 > k) == true. Swap all structs, not only name member (if not, what for sorting vanity?). For example:

void Sort(Roster& r)
{
StudentRec temp;
int next;

for (int k = 0; k < r.numStudent - 1; k++)
{
next = k;
for(int j = k+1; j < r.numStudent; j++)
if(strcmp(r.student[j].name,r.student[k].name) < 0)
next = j;
if (next != k) // don't swap if left min
{
//Swapping buffer
temp = r.student[next];
r.student[next] = r.student[k];
r.student[k] = temp;
}
}
}

 

[Federal102]

Since this is C++ code, you could try making use of the STL.

Something like..

struct StudentRec
{
 bool operator < (StudentRec &rhs)
 {
  return name < rhs.name;
 }
 string name;
 float average;
};

struct Roster
{
 vector<StudentRec> student;
};

int main()
{
 //set up test data
 StudentRec s1;
 StudentRec s2;
 StudentRec s3;
 s1.name = &quot;Smith&quot;;
 s2.name = &quot;Jones&quot;;
 s3.name = &quot;Lopez&quot;;

 Roster r;
 r.student.push_back(s1);
 r.student.push_back(s2);
 r.student.push_back(s3);
 //end test data set up

 //sort Roster
 sort(r.student.begin(), r.student.end());

 return 0;
};