leetcode120.三角形最小路径

 

class Solution {
    public int minimumTotal(List<List<Integer>> triangle) {
        int[][] dp = new int[triangle.size()][triangle.size()];
        //dp初始化
        dp[0][0] = triangle.get(0).get(0);
        for (int i = 1; i < dp.length; i++) {
            dp[i][0] = dp[i - 1][0] + triangle.get(i).get(0);
            dp[i][i] = dp[i - 1][i - 1] + triangle.get(i).get(i);
        }
        //动态规划
        for (int i = 2; i < triangle.size(); i++) {
            for (int j = 1; j < i; j++) {
                dp[i][j] = triangle.get(i).get(j) + Math.min(dp[i - 1][j], dp[i - 1][j - 1]);
            }
        }
        //选取结果中的最小值
        return Arrays.stream(dp[triangle.size() - 1]).min().getAsInt();
    }
}