Leetcode------Triangle

Title:	Triangle
Pass Rate:	27.1%
Difficulty:	Medium

Given a triangle, find the minimum path sum from top to bottom. Each step of the move to adjacent numbers on the row below.

For example, given the following triangle

[     2],    [3, 4],   [6,5, 7],  [4,1, 8,3]]

The minimum path sum from top to bottom 11 is (i.e., 2 + 3 + 5 + 1 = 11).

Note:
Bonus Point If-able to does this using only O(n) extra space, where n is the total number of rows in the triangle.

Dynamic programming topics, bottom-up, minimum and must be the minimum of each row, then from below to start merging upward, the formula is res[i][j]=res[i+1][j]+res[i+1][j+1]

The formula explanation starts with the last line, each time the smaller values of J and J+1 are selected plus the J assignment of the previous line to J, and so on

1  Public classSolution {2      Public intMinimumtotal (list<list<integer>>triangle) {3         if(Triangle.size () ==1)returnTriangle.get (0). Get (0);4         int[] res=New int[Triangle.size ()];5          for(intI=0;i<triangle.size (); i++){6Res[i]=triangle.get (Triangle.size ()-1). get (i);7         }8          for(intI=triangle.size () -2;i>=0;i--){9              for(intJ=0;j<triangle.get (i). Size (); j + +){TenRes[j]=math.min (res[j],res[j+1]) +Triangle.get (i). get (j); One             } A         } -         returnRes[0]; -     } the}

Leetcode------Triangle