Add problem 7 .

1 files changed, 18 insertions, 0 deletions

diff --git a/cpp/7.cpp b/cpp/7.cpp
new file mode 100644
index 0000000..a1a05c1
--- /dev/null
+++ b/cpp/7.cpp
@@ -0,0 +1,18 @@
+class Solution

+{

+public:

+    int reverse(int x)

+    {

+        int result = 0;

+        while (x != 0)

+        {

+            int digit = x % 10;

+            x /= 10;

+            if (__builtin_smul_overflow(result, 10, &result))

+                return 0;

+            if (__builtin_sadd_overflow(result, digit, &result))

+                return 0;

+        }

+        return result;

+    }

+};