fix: wrong answer of find_common_string
#1816
| Job | Run time |
|---|---|
| 33s | |
| 56s | |
| 55s | |
| 40s | |
| 40s | |
| 3m 44s |
find_common_string
#1816
| Job | Run time |
|---|---|
| 33s | |
| 56s | |
| 55s | |
| 40s | |
| 40s | |
| 3m 44s |