120. Triangle (java)

Author: bluesword12350

solution/0120.Triangle/Solution.java

@@ -0,0 +1,18 @@
+class Solution {
+    private int[][] cache = null;
+    public int minimumTotal(List<List<Integer>> triangle) {
+        int n = triangle.size();
+        cache = new int[n][triangle.get(n - 1).size()];
+        for (int[] row : cache) Arrays.fill(row, -1);
+        return dfs(triangle,0,0);
+    }
+    private int dfs(List<List<Integer>> triangle, int row, int col) {
+        if (row == triangle.size()) return 0;
+        if (cache[row][col] != -1) return cache[row][col];
+        int l = dfs(triangle,row+1,col);
+        int r = dfs(triangle,row+1,col+1);
+        int res = Math.min(l,r)+triangle.get(row).get(col);
+        cache[row][col] = res;
+        return res;
+    }
+}