Create 370.Range-Addition.cpp

Segment_Tree/370.Range-Addition/370.Range-Addition.cpp

@@ -0,0 +1,76 @@
+class Solution {
+    class SegNode
+    {
+        public:
+
+        int begin, end, status;
+        SegNode* left;
+        SegNode* right;
+        SegNode(int a, int b, int s)
+        {
+            begin = a;
+            end = b;
+            status = s;
+            left = NULL;
+            right = NULL;
+        }
+
+        void remove(SegNode* & node)
+        {
+            if (node==NULL) return;
+            remove(node->left);
+            remove(node->right);
+            delete node;
+            node=NULL;
+        }
+
+        int setStatus(int a, int b, int s)
+        {
+            if (b<=begin || a>=end)
+            {
+                return status;
+            }
+            if (a<=begin && end<=b && left==NULL)
+            {                
+                status += s;
+                return status;
+            }
+            int mid = (end-begin)/2+begin;
+            if (left==NULL)
+            {              
+                left = new SegNode(begin,mid,status);
+                right = new SegNode(mid,end,status);
+            }
+            int leftStatus = left->setStatus(a,b,s);
+            int rightStatus = right->setStatus(a,b,s);
+            return max(leftStatus,rightStatus);
+        }
+    };
+
+public:
+    vector<int> getModifiedArray(int length, vector<vector<int>>& updates) 
+    {
+        SegNode* root = new SegNode(0,length,0);
+
+        for (int i=0; i<updates.size(); i++)
+            root->setStatus(updates[i][0],updates[i][1]+1,updates[i][2]);
+
+        vector<int>results(length);
+        DFS(root,results);
+        return results;
+    }
+
+    void DFS(SegNode* node, vector<int>& results)
+    {
+        if (node==NULL)
+            return;
+        if (node->left!=NULL)
+        {
+            DFS(node->left,results);
+            DFS(node->right,results);
+            return;
+        }
+        for (int i=node->begin; i<node->end; i++)
+            results[i] = node->status;
+    }
+};