Create count-square-sum-triples.cpp

Author: kamyu104

C++/count-square-sum-triples.cpp

@@ -0,0 +1,19 @@
+// Time:  O(n^2)
+// Space: O(n)
+
+class Solution {
+public:
+    int countTriples(int n) {
+        unordered_set<int> lookup;
+        for (int i = 1; i <= n; ++i) {
+            lookup.emplace(i * i);
+        }
+        int result = 0;
+        for (int i = 1; i <= n; ++i) {
+            for (int j = 1; j <= n; ++j) {
+                result += lookup.count(i * i + j * j);
+            }
+        }
+        return result;
+    }
+};