/
index.ts
37 lines (36 loc) · 1.05 KB
/
index.ts
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
29
30
31
32
33
34
35
36
37
export default interface RLEIterator {
next(n: number): number;
}
function* RLEGenerator(encoding: number[]) {
for (let i = 0; i < encoding.length; i += 2) {
yield { count: encoding[i], value: encoding[i + 1] };
}
}
export default function RLEIterator(
encoding: number[],
): RLEIterator {
const generator = (RLEGenerator)(encoding);
let count = 0;
let value = 0;
let done = false;
return {
next(n: number): number {
if (done) return -1;
while (n > 0 && !done) {
if (count) {
const delta = Math.min(count, n);
n -= delta;
count -= delta;
if (n === 0) return value;
} else {
const result = generator.next();
done = !!result.done;
if (result.done) return -1;
value = result.value.value;
count = result.value.count;
}
}
return -1;
},
};
}