0954 added.

liuyubobobo · liuyubobobo · commit 176c7053df44 · 2018-12-12T17:37:00.000-08:00
diff --git a/0954-canReorderDoubled/cpp-0954/CMakeLists.txt b/0954-canReorderDoubled/cpp-0954/CMakeLists.txt
@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.13)
+project(B)
+
+set(CMAKE_CXX_STANDARD 11)
+
+add_executable(B main.cpp)
diff --git a/0954-canReorderDoubled/cpp-0954/main.cpp b/0954-canReorderDoubled/cpp-0954/main.cpp
@@ -0,0 +1,49 @@
+/// Source : https://leetcode.com/problems/array-of-doubled-pairs/
+/// Author : liuyubobobo
+/// Time   : 2018-12-12
+
+#include <iostream>
+#include <vector>
+#include <unordered_map>
+
+using namespace std;
+
+
+/// Greedy, from large absolute value to small absolute value
+/// Time Complexity: O(nlogn)
+/// Space Complexity: O(n)
+class Solution {
+public:
+    bool canReorderDoubled(vector<int>& A) {
+
+        unordered_map<int, int> freq;
+        for(int a: A)
+            freq[a] ++;
+
+        sort(A.begin(), A.end(), [](int a, int b){return abs(a) < abs(b);});
+//        for(int a: A)
+//            cout << a << " ";
+//        cout << endl;
+
+        for(int a: A){
+            if(freq[a]){
+                if(!freq[2 * a])
+                    return false;
+                freq[a] --;
+                if(!freq[2 * a])
+                    return false;
+                freq[2 * a] --;
+            }
+        }
+        return true;
+    }
+};
+
+
+int main() {
+
+    vector<int> A1 = {4, -2, 2, -4};
+    cout << Solution().canReorderDoubled(A1) << endl;
+
+    return 0;
+}
diff --git a/readme.md b/readme.md
@@ -613,6 +613,6 @@ email: [liuyubobobo@gmail.com](mailto:liuyubobobo@gmail.com)
 | 951 | [Flip Equivalent Binary Trees](https://leetcode.com/problems/flip-equivalent-binary-trees/) | [solution](https://leetcode.com/problems/flip-equivalent-binary-trees/solution/) | [C++](0951-Flip-Equivalent-Binary-Trees/cpp-0951/) | | |
 | 952 | [Largest Component Size by Common Factor](https://leetcode.com/problems/largest-component-size-by-common-factor/) | [solution](https://leetcode.com/problems/largest-component-size-by-common-factor/solution/) | [C++](0952-Largest-Component-Size-by-Common-Factor/cpp-0952/) | | |
 | 953 | [isAlienSorted](https://leetcode.com/problems/verifying-an-alien-dictionary/) | [solution](https://leetcode.com/problems/verifying-an-alien-dictionary/solution/) | [C++](0953-isAlienSorted/cpp-0953/) | | |
-| | | | | | |
+| 954 | [Array of Doubled Pairs](https://leetcode.com/problems/array-of-doubled-pairs/) | [solution](https://leetcode.com/problems/array-of-doubled-pairs/solution/) | [C++](0954-Array-of-Doubled-Pairs/cpp-0954/) | | |
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