Get rid of unused variable.

src/main.rs

@@ -31,7 +31,7 @@ fn main() {
 	{
 		let mut nums:Vec<u32> = (1..size+1).collect();
 
-		for _i in 0..nums.len()
+		while nums.len() > 0
 		{
 			let rand_i:usize = rand::random::<usize>() % nums.len();
 			boxes.push(nums[rand_i]);