// Floyd's triangle is a right-angled triangular of natural numbers
fn main() {
let rows = 7;
let mut n = 1;
for i in 1..=rows {
for _j in 1..=i {
print!("{} ", n);
n += 1;
}
println!();
}
}
/*
run:
1
2 3
4 5 6
7 8 9 10
11 12 13 14 15
16 17 18 19 20 21
22 23 24 25 26 27 28
*/