[Python3] freq table
Please check out this commit for solutions of biweekly 62. \n\nclass Solution:\n    def numOfPairs(self, nums: List[str], target: str) -> int:\n        freq = C
Please check out this [commit](https://github.com/gaosanyong/leetcode/commit/182350e41572fb26ffb8c44204b037cc9f0e5035) for solutions of biweekly 62. \n```\nclass Solution:\n    def numOfPairs(self, nums: List[str], target: str) -> int:\n        freq = Counter(nums)\n        ans = 0 \n        for k, v in freq.items(): \n            if target.startswith(k): \n                suffix = target[len(k):]\n                ans += v * freq[suffix]\n                if k == suffix: ans -= freq[suffix]\n        return ans \n```
['Python3']