## 问题描述

You are given n balloons, indexed from 0 to n - 1. Each balloon is painted with a number on it represented by an array nums. You are asked to burst all the balloons.

If you burst the ith balloon, you will get `nums[left] * nums[i] * nums[right]`

coins. Here left and right are adjacent indices of i. After the burst, the left and right then becomes adjacent.