Given an array which consists of only 0, 1 and 2 sort the array without using any sorting algorithm in C

December 13, 2023

Sort the array with elements 0, 1 and 2 in C

Here, in this page we will discuss the program to sort the array with elements 0, 1 and 2 in C . We use the concept of counting the frequency of 0, 1 and 2 . We are giving with the size of the array along with array elements .We have to print sorted array.

Example : Input : n= 5
arr[5] = { 0, 1, 2, 0, 0}

Output : 0 0 0 1 2

Algorithm :

Take the size of the array from the user and store it in variable say n.
Now, declare a vector of size n and take the n elements of the vector say arr from the user.
Declare three variables say count_0, count_1 and count_2 and initialize them with 0. (These variable will hold the count of the frequency of 0, 1 and 2).
Now, iterate over the array and increase the value of variable count_0 if arr[i] is 0 , count_1 if arr[i] is 1 and count_2 if arr[i] is 2 by value 1.
Now, clear the vector.
Declare variable say i and initialized it with 0.
Run a while loop till count_0 is not zero and inside while loop set arr[i++] =0.
Again Run a while loop till count_1 is not zero and inside while loop set arr[i++] =1.
At last again run while loop till count_2 is not zero and inside while loop set arr[i++] =2.
Finally the array get sorted without using any sorting technique and print the array.

C Code

Run

#include

int main(){

int n;
n=4;

int arr[n]={1,5,6,7};
int count_0=0, count_1 =0, count_2=0;

for(int i=0; i<n; i++){

if(arr[i]==0) count_0++;
else if(arr[i]==1) count_1++;
else count_2++;
}
int i=0;
while(count_0--) arr[i++]=0;
while(count_1--) arr[i++]=1;
while(count_2--) arr[i++]=2;
for(int i=0; i<n; i++)
printf("%d ", arr[i]);
return 0;
}