nested list weight sum

fishercoder1534 · fishercoder1534 · commit 89fff0f45de8 · 2016-08-19T08:30:28.000-07:00
diff --git a/EASY/src/easy/NestedListWeightSum.java b/EASY/src/easy/NestedListWeightSum.java
@@ -0,0 +1,41 @@
+package easy;
+
+import java.util.List;
+
+import classes.NestedInteger;
+
+public class NestedListWeightSum {
+    class Solution_with_global_sum {
+        private int sum = 0;
+
+        public int depthSum(List<NestedInteger> nestedList) {
+            return dfs(nestedList, 1);
+        }
+
+        private int dfs(List<NestedInteger> nestedList, int depth) {
+            for (NestedInteger ni : nestedList) {
+                if (ni.isInteger()) {
+                    sum += depth * ni.getInteger();
+                } else {
+                    dfs(ni.getList(), depth + 1);
+                }
+            }
+            return sum;
+        }
+    }
+    
+    class Solution_with_local_sum {
+        public int depthSum(List<NestedInteger> nestedList) {
+            return dfs(nestedList, 1);
+        }
+
+        private int dfs(List<NestedInteger> nestedList, int depth) {
+            int sum = 0;
+            for(NestedInteger ni : nestedList){
+                sum += ni.isInteger() ? depth*ni.getInteger() : dfs(ni.getList(), depth+1);
+            }
+            return sum;
+        }
+    }
+
+}
