7. 整数反转 考虑溢出
class Solution {public int reverse(int x) {int ans = 0;while (x != 0) {int pop = x % 10;if (ans > Integer.MAX_VALUE / 10 || (ans == Integer.MAX_VALUE / 10 && pop > 7))return 0;if (ans < Integer.MIN_VALUE / 10 || (ans == Integer.MIN_VALUE / 10 && pop < -8))return 0;ans = ans * 10 + pop;x /= 10;}return ans;}}
| x | pop | ans |
|---|---|---|
| 1234 | 0 | |
| 123 | 4 | 4 |
| 12 | 3 | 43 |
| 1 | 2 | 432 |
| 0 | 1 | 4321 |
