# C Program for Selection Sort

Write a Program to Sort an Array using Selection Sort in C with a practical example of for loop, while loop, and functions.

## C Program for Selection Sort using For Loop

This program uses Nested For Loop to sort the array elements using selection sort.

```// using nested for loop
#include <stdio.h>
int main()
{
int a[100], number, i, j, temp;
printf("\n Please Enter the total Number of Elements  :  ");
scanf("%d", &number);
printf("\n Please Enter the Array Elements  :  ");
for(i = 0; i < number; i++)
scanf("%d", &a[i]);

for(i = 0; i < number; i++) {
for(j = i + 1; j < number; j++) {
if(a[i] > a[j]) {
temp = a[i];
a[i] = a[j];
a[j] = temp;
}
}
}
printf("\n Selection Sort Result : ");
for(i = 0; i < number; i++)  {
printf(" %d \t", a[i]);
}
printf("\n");
return 0;
}```

Here, in this C selection sort program, the For Loop will make sure that the number is between 1 and maximum size – 1.
First For Loop – First Iteration: for(i = 0; 0 < 4; 0++)
The condition is True so, it will enter into the second for loop.

Second For Loop – First Iteration: for(j = 1; 1 < 4; 1++) – This condition is True
if(a[0] > a[1]) => (10 > 9) – This condition is True
temp = 10
a[i] = a[j] => a[0] = 9
a[j] = temp => a[1] = 10
Now the array will be 9 10 0 11.

Second For Loop – Second Iteration: for(j = 2; 2 < 4; 2++) – True
if(a[0] > a[2]) => (9 > 0) – Condition is True
temp = a[0] => temp = 9
a[0] = a[2] => a[0] = 0
a[2] = temp => a[2] = 9
Now the array will be 0 10 9 11.

Do the same for the remaining Iterations of the second for loop. Next, repeat the same with the first C Programming for loop.

### C Program for Selection Sort using for loop

In this selection sort program, we used a slightly different approach to demonstrate this.

```#include <stdio.h>
int main()
{
int a[100], num, min, i, j, temp;
printf("\n Please Enter the total Elements  :  ");
scanf("%d", &num);
printf("\n Please Enter the Array Elements  :  ");
for(i = 0; i < num; i++)
scanf("%d", &a[i]);

for(i = 0; i < num - 1; i++) {
min = i;
for(j = i + 1; j < num; j++) {
if(a[min] > a[j]) {
min = j;
}
}
if(min != i)
{
temp = a[i];
a[i] = a[min];
a[min] = temp;
}
}
printf("\n Result : ");
for(i = 0; i < num; i++)  {
printf(" %d \t", a[i]);
}
printf("\n");
return 0;
}```
``````Please Enter the total Elements  :  5

Please Enter the Array Elements  :  10 2 19 0 10

Result :  0 	 2 	 10 	 10 	 19 	``````

## C Selection Sort Program using While Loop

In this program, we replaced the for loop with While Loop.

```#include <stdio.h>
int main()
{
int a[100], val, i, j, temp;
printf("\n Please Enter the total No. of Elements  :  ");
scanf("%d", &val);
printf("\n Please Enter the Array Elements  :  ");
for(i = 0; i < val; i++)
scanf("%d", &a[i]);

i = 0;
while( i < val) {
j = i + 1;
while( j < val) {
if(a[i] > a[j]) {
temp = a[i];
a[i] = a[j];
a[j] = temp;
}
j++;
}
i++;
}
printf("\n Result : ");
for(i = 0; i < val; i++)  {
printf(" %d \t", a[i]);
}
printf("\n");
return 0;
}```
`````` Please Enter the total No. of Elements  :  7

Please Enter the Array Elements  :  20 0 25 19 4 22 16

Result :  0 	 4 	 16 	 19 	 20 	 22 	 25 	``````

## C Selection Sort Program using Functions

This program uses Functions to separate the logic and Pointers to swap and rearrange the array elements by using this selection sort.

```#include <stdio.h>
void Swap(int *x, int *y) {
int Temp;
Temp = *x;
*x = *y;
*y = Temp;
}
void selFunc(int a[], int number) {
int i, j;
for(i = 0; i < number; i++) {
for(j = i + 1; j < number; j++) {
if(a[i] > a[j]) {
Swap(&a[i], &a[j]);
}
}
}
}
int main()
{
int a[100], number, i;
printf("\n Please Enter the total Number of Elements  :  ");
scanf("%d", &number);
printf("\n Please Enter the Array Elements  :  ");
for(i = 0; i < number; i++)
scanf("%d", &a[i]);

selFuc(a, number);
printf("\n Result : ");
for(i = 0; i < number; i++)  {
printf(" %d \t", a[i]);
}
printf("\n");
return 0;
}```
``````Please Enter the total Number of Elements  :  6

Please Enter the Array Elements  :  12 3 0 22 19 -8

Result :  -8 	 0 	 3 	 12 	 19 	 22 	``````