120. Triangle

Given a triangle, find the minimum path sum from top to bottom. Each step you may 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 is 11 (i.e., 2 + 3 + 5 + 1 = 11).

S: 坐标型DP

自底向上DP

    int minimumTotal(vector<vector<int>>& triangle) {
        int size = triangle.size();
        if (size < 1) {
            return 0;
        }
        vector<int> cache = triangle[size-1];
        for (int i = size - 2; i >= 0; --i) {
            for (int j = 0; j <= i; ++j) {
                cache[j] = triangle[i][j] + min(cache[j], cache[j+1]);
            }
        }
        return cache[0];
    }