From db99fe1bae1a73f030bb3c5a00f04eca7ce07c3e Mon Sep 17 00:00:00 2001
From: Hao Chen <haoel@hotmail.com>
Date: Fri, 29 Mar 2019 11:09:37 +0800
Subject: [PATCH] no tricky solution

---
 algorithms/cpp/twoSum/twoSum.cpp | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/algorithms/cpp/twoSum/twoSum.cpp b/algorithms/cpp/twoSum/twoSum.cpp
index 6ef67fa77..dc0680f8a 100644
--- a/algorithms/cpp/twoSum/twoSum.cpp
+++ b/algorithms/cpp/twoSum/twoSum.cpp
@@ -66,4 +66,19 @@ class Solution {
         }
         return result;
     }
+
+    // we also can store nums[i] into map, and find target - nums[i]
+    vector<int> twoSum(vector<int>& nums, int target) {
+        unordered_map<int, int> m;
+        vector<int> result;
+        for (int i=0; i<nums.size(); i++) {
+            if ( m.find(target - nums[i]) == m.end() ) {
+                m[nums[i]] = i;
+            }else{
+                result.push_back(m[target - nums[i]]);
+                result.push_back(i);
+            }
+        }
+        return result;
+    }
 };