leetcode1105 Filling Bookcase Shelves

思路：

dp[i]表示摆放好前i本书所需要的最小代价。

实现：

 class Solution
 {
 public:
     int minHeightShelves(vector<vector<int>>& books, int shelf_width)
     {
         int n = books.size();
         vector<int> dp(n + , );
         dp[] = ; dp[] = books[][];
         for (int i = ; i <= n; i++)
         {
             dp[i] = dp[i - ] + books[i - ][];
             int sum = books[i - ][], maxn = books[i - ][];
             for (int j = i - ; j >= ; j--)
             {
                 if (sum + books[j - ][] > shelf_width) break;
                 maxn = max(maxn, books[j - ][]);
                 dp[i] = min(dp[i], dp[j - ] + maxn);
                 sum += books[j - ][];
             }
         }
         return dp[n];
     }
 }