#1470. Pku1738 An old Stone Game

There is an old stone game. At the beginning of the game the player picks n(1<=n<=50000) piles of stones in a line. The goal is to merge the stones in one pile observing the following rules: At each step of the game,the player can merge two adjoining piles to a new pile.The score is the number of stones in the new pile. You are to write a program to determine the minimum of the total score. 就是最简单的石子合并问题.