Create print_inverted_pyramid_pattern.rs

Adding Rust function to print an inverted pyramid pattern for issue #3668

program/program/print-inverted-pyramid-pattern/print_inverted_pyramid_pattern.rs

@@ -0,0 +1,39 @@
+//  	Rust function to print an inverted pyramid pattern
+//Example:
+//  Input   : 5
+//  Output : 
+//	1 2 3 4 5
+//	1 2 3 4 
+//	1 2 3
+//	1 2
+//	1
+
+use std::io;
+
+fn print_inverted_triangle(n: u32) {
+
+    let mut limit = n+1;
+
+    for _i in 1 .. n+1 {
+
+        for j in 1 .. limit {
+            print!("{} ", j);
+        }
+
+	limit = limit - 1;
+        println!();
+    }
+}
+
+fn main() {
+
+	// the input string and this main function can be removed. This is simply for testing
+
+	println!("Enter the number of levels to print");
+	let mut input_num = String::new();
+	let _rtrn = io::stdin().read_line(&mut input_num);
+	let n: u32 = input_num.trim().parse().expect("Input not an integer");	
+
+	// example of how to call the function and print out the results of the inverted pyramid.
+    	print_inverted_triangle(n);
+}