# Leetcode 371 - Sum of two integers

`Note:`

- Not hard to come up with bit wise methods.
- The result must be a
`32-bit`

integer. We init`res`

as`0`

. - Use
`prev`

to carry extra 1 from prev digit. - For each digit, how should we add the result into
`res`

? - Use
`curSum << i`

, it will right shift`1`

and use`|`

to add up with`res`

. - Should we care about
`negative`

numbers?- No. Actually, when we do
`a >> 1`

and`a < 0`

, the left most will be filled with 0. If itâ€™s a while loop, it would be a loop hole. But we only do this`32`

times. So, it will def terminate.

- No. Actually, when we do

`Question:`

Given two integers a and b, return the sum of the two integers without using the operators + and -.

`Example:`

1 | Input: a = 1, b = 2 |

`Code:`

1 | /** |