第二题，python版本，c++不熟悉，真的写不出来 # 区间动态规划 def minInsertions(s) : n = len(s) dp = [[0] * n for _ in range(n)] for span in range(2, n + 1): for i in range(n - span + 1): j = i + span - 1 dp[i][j] = min(dp[i + 1][j], dp[i][j - 1]) + 1 if s[i] == s[j]: dp[i][j] = min(dp[i][j], dp[i + 1][j - 1]) return n-dp[0][n-1]-1