I have an insertion sort that was working when it sorted integers, however I had to change it to sort an array of structs for a different project. The array is 10 people's names and ages. The array is first passed to a sorting function and then a for loop is set to iterate through the array. I think the issue I am having is the array is not looping correctly because the print out of the new array is in a mixed up order still. Here is the code I have...
#include <stdio.h>
#define SWAP(x,y) do {typeof(x) SWAP = x; x=y; y=SWAP;} while (0)
typedef struct Person{
int age;
char name[10];
}Person;
//-----------------------------
void sort(Person* arr,int n){
int i, x, y;
for (i=1;i<n;i++){
x=arr[i].age;
y = i-1;
while(y>=0 && arr[y].age > x){
arr[y+1]=arr[y];
y=y-1;
}
SWAP(arr[y+1],arr[i]);
}
}
int main(){
struct Person p1 = {26, "devin"};
struct Person p2 = {28, "bob"};
struct Person p3 = {22, "derric"};
struct Person p4 = {20, "amy"};
struct Person p5 = {19, "melvin"};
struct Person p6 = {17, "ashley"};
struct Person p7 = {31, "haley"};
struct Person p8 = {32, "larry"};
struct Person p9 = {24, "ben"};
struct Person p10 = {40, "bobby"};
struct Person arr[] = {p1,p2,p3,p4,p5,p6,p7,p8,p9,p10};
int n = sizeof(arr)/sizeof(arr[0]);
printf("--Array Before Sort--\n");
print(arr, n);
printf("--Array After Sort--\n");
sort(arr,n);
//printf("\n--Sorted Array--\n");
print(arr,n);
}
The code is missing the print function because I believe that is working properly and I'm trying to condense what I need help with. I believe the issue is in the for and while loops in the sort function. Here is the output...
--Array Before Sort--
26 devin, 28 bob, 22 derric, 20 amy, 19 melvin, 17 ashley, 31 haley, 32 larry, 24 ben, 40 bobby,
--Array After Sort--
32 larry, 28 bob, 28 bob, 28 bob, 28 bob, 26 devin, 28 bob, 31 haley, 32 larry, 40 bobby,
The names are supposed to be sorted from youngest to oldest. Any ideas?
You just need to make a few small changes to sort function:
void sort(Person* arr, int n)
{
int i, y;
for (i = 1; i < n; i++){
Person x = arr[i];
y = i - 1;
while (y >= 0 && arr[y].age > x.age){
arr[y + 1] = arr[y];
y = y - 1;
}
SWAP(arr[y + 1], x);
}
}
I would also replace SWAP(arr[y+1], x);
with just arr[y+1] = x;
because it makes code more readable and it probably is better for overall performance.