Leetcode-312 Burst Balloons(戳气球)

 1 #define maxn 1000000
 2 #define _for(i,a,b) for(int i = (a);i < (b);i ++)
 3 #define pb push_back
 4 class Solution
 5 {
 6     public:
 7         int dp[503][503];
 8         int ms(vector<int>& nums,int le,int ri)
 9         {
10             
11             if(le==ri-1)
12                 return 0;
13             if(dp[le][ri]!=-1)
14                 return dp[le][ri];
15             
16             int rnt = INT_MIN;
17             for(int i = le+1;i < ri;i ++)
18                 rnt = max(rnt,ms(nums,le,i)+ms(nums,i,ri)
19                           +nums[le]*nums[i]*nums[ri]);
20             return dp[le][ri] = rnt;
21         }
22         int maxCoins(vector<int>& nums)
23         {
24             memset(dp,-1,sizeof(dp));
25             vector<int> arr(nums.size()+2);
26             _for(i,0,nums.size())
27                 arr[i+1] = nums[i];
28             arr[0] = arr[nums.size()+1] = 1;
29             return ms(arr,0,nums.size()+1); 
30         }
31 };