Probability -(noob)
hello,i need a little help with my project that give all Probability to (1,2,3) here's my code that doesn't work like i want in Part4
please i need help thanks 
Code:
#include <stdio.h>
#include <stdlib.h>
main()
{
int arr[3]={0,1,2};
int i;
arr[0]=1;
arr[1]=2;
arr[2]=3;
for (i=0;i<3;i++) //Part1 (123)
{
printf("%d",arr[i]);
}
printf("\n");
for (i=0;i<2;i++) ////Part2 (12)
{
printf("%d",arr[i]);
}
printf("\n");
for (i=0;i<3;i= i+2) //Part3 (13)
{
printf("%d",arr[i]);
}
printf("\n"); //part4 (213)
for (i=2;i>1;i=i-1)
{
printf("%d",arr[i]);
}
}
