balance.rs

pub fn balance<T: Into<String>>(input: T) -> bool {
    let mut stk = Vec::new();
    for c in input.into().chars(){
        match c {
            a @ '(' | a @ '{' |a @ '[' => {
                stk.push(a);
            },
            a @ ')' |a @ '}' |a @ ']' => {
                match stk.pop() {
                    Some(t) => {
                        if a == ')' && t != '(' { return false;}
                        if a == '}' && t != '{' { return false;}
                        if a == ']' && t != '[' { return false;}
                    },
                    None => return false,
                }
            },
            _ => (),
        }
    }
    stk.len() == 0
}

fn main() {
    assert_eq!(balance("()"), true);
    assert_eq!(balance("("), false);
    assert_eq!(balance("([])"), true);
    assert_eq!(balance("([{]})"), false);
    assert_eq!(balance("("), false);
    assert_eq!(balance("{([])}()"), true);
    println!("TEST PASSED")
}