Keep substracting divisor and double it each time.

```
public int divide(int a, int b) {
if(a==Integer.MIN_VALUE){
if(b==-1) return Integer.MAX_VALUE;
}
long x = a < 0 ? -(long)a : (long)a;
long y = b < 0 ? -(long)b : (long)b;
int res = recurse(x, y, 1);
if(a < 0 && b < 0) return res;
if(a < 0 || b < 0) return -res;
return res;
}
public int recurse(long x, long y, int count) {
if(x <= 0 || count==0) return 0;
if(y > x) return recurse(x, y >>> 1, count >>> 1); //overshot, so divide and try again.
else return recurse(x-y, y+y, count+count)+count;
}
```