Create 303_Range_Sum_Query_Immutable.cc

cpppy · web-flow · commit 04527c8edbc6 · 2016-08-23T21:12:55.000+08:00
diff --git a/303_Range_Sum_Query_Immutable.cc b/303_Range_Sum_Query_Immutable.cc
@@ -0,0 +1,27 @@
+class NumArray {
+public:
+    NumArray(vector<int> &nums) {
+        if(nums.size()==0)  return;
+        int tmp=0;
+        for(int i=0;i<nums.size();++i){
+            tmp+=nums[i];
+            sums.push_back(tmp);
+        }
+    }
+
+    int sumRange(int i, int j) {
+        if(i>j) return 0;
+        if(i==0)    return sums[j];
+        else    return sums[j]-sums[i-1];
+    }
+    
+    
+private:
+    vector<int> sums;
+};
+
+
+// Your NumArray object will be instantiated and called as such:
+// NumArray numArray(nums);
+// numArray.sumRange(0, 1);
+// numArray.sumRange(1, 2);
