struct RLEIterator {
prefix: Vec<usize>,
values: Vec<i32>,
index: usize,
size: usize,
}
impl RLEIterator {
fn new(a: Vec<i32>) -> Self {
let mut prefix = vec![];
let mut values = vec![];
let n = a.len();
let index = 0;
let mut prev = 0;
for i in 0..n / 2 {
let time = a[i * 2] as usize;
if time != 0 {
prev += time;
prefix.push(prev);
values.push(a[i * 2 + 1]);
}
}
let size = values.len();
RLEIterator {
prefix,
values,
index,
size,
}
}
fn next(&mut self, n: i32) -> i32 {
self.index += n as usize;
match self.prefix.binary_search(&self.index) {
Ok(i) => self.values[i],
Err(i) => {
if i < self.size {
self.values[i]
} else {
-1
}
}
}
}
}
#[test]
fn test() {
let mut obj = RLEIterator::new(vec![3, 8, 0, 9, 2, 5]);
assert_eq!(obj.next(2), 8);
assert_eq!(obj.next(1), 8);
assert_eq!(obj.next(1), 5);
assert_eq!(obj.next(2), -1);
}