The idea is very easy:

- sort the array.
- find the "shortest" common overlapping interval of balloons (if possible) where shoots an arrow.
- repeat step 2 until traverse all balloons.

```
public int findMinArrowShots(int[][] points) {
if(points.length <= 1) return points.length;
Arrays.sort(points, (a, b) -> a[0] == b[0]? a[1]-b[1] : a[0]-b[0]);
int count = 1;
int minEnd = points[0][1];
for(int i = 1; i < points.length; i++) {
if(points[i][0] <= minEnd) {
minEnd = Math.min(minEnd, points[i][1]);
continue;
}
count++;
minEnd = points[i][1];
}
return count;
}
```