距离  acm省赛25天，现在开始学习dp不知道会不会太晚，先来一道基础题感受下  dp 思维 数塔 Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 42855    Accepted Submission(s): 25352