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@MightyPork
Created December 21, 2018 21:14
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use std::io;
use std::io::Write;
fn fibo(n:u32) -> u32 {
if n <= 2 {
1
} else {
let mut prev1 = 1;
let mut prev2 = 1;
for _n in 2..n {
let next = prev1 + prev2;
prev2 = prev1;
prev1 = next;
}
prev1
}
}
fn main() {
let mut s;
let num : u32 = loop {
print!("Enter a number: ");
io::stdout().flush()
.expect("Failed to flush stdout");
s = String::new();
io::stdin().read_line(&mut s)
.expect("Failed to read line");
s = s.trim().to_string();
if s.len() == 0 {
println!("");
std::process::exit(1);
}
let _ : u32 = match s.parse() {
Ok(val) => {
break val;
},
Err(_) => {
println!("Bad num: {}", s);
continue;
},
};
};
println!("{}-th Fibonacci number is: {}",
num,
fibo(num)
);
}
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