巧用 Python 求解数列积之和，附输入输出及样例详解！

```python MOD = 1000000007 n, m, k = map(int, input().split()) restrictions = {} for _ in range(k): x, y = map(int, input().split()) if x in restrictions: restrictions[x].add(y) else: restrictions[x] = {y} total_product_sum = 1 for i in range(1, m + 1): if i in restrictions: available_values = [j for j in range(1, n + 1) if j not in restrictions[i]] current_sum = sum(available_values) % MOD else: current_sum = (n * (n + 1) // 2) % MOD total_product_sum = (total_product_sum * current_sum) % MOD print(total_product_sum) ``` 此代码先读取输入，将限制条件存储在字典`restrictions`里。对每个位置`i`，检查是否存在限制，若有则计算可用值的和，没有则计算`1`到`n`的和。最终将每个位置的和相乘并取模得到结果。 ######[AI问答 | 263点数解答 | 2026-01-24 13:02:54]