Merge branch 'master' into leetcode-9

leetcode/README.md

@@ -10,6 +10,7 @@ LeetCode
 |2|[Add Two Numbers](https://leetcode.com/problems/add-two-numbers/) | [C](./src/2.c)|Medium|
 |3|[Longest Substring Without Repeating Characters](https://leetcode.com/problems/longest-substring-without-repeating-characters/) | [C](./src/3.c)|Medium|
 |4|[Median of Two Sorted Arrays](https://leetcode.com/problems/median-of-two-sorted-arrays/) | [C](./src/4.c)|Hard|
+|7|[Reverse Integer](https://leetcode.com/problems/reverse-integer/) | [C](./src/7.c)|Easy|
 |9|[Palindrome Number](https://leetcode.com/problems/palindrome-number/) | [C](./src/9.c)|Easy|
 |13|[Roman to Integer](https://leetcode.com/problems/roman-to-integer/) | [C](./src/13.c)|Easy|
 |20|[Valid Parentheses](https://leetcode.com/problems/valid-parentheses/) | [C](./src/20.c)|Easy|

leetcode/src/7.c

@@ -0,0 +1,13 @@
+#include <limits.h>
+
+int reverse(int x){
+    int rev = 0;
+        while (x != 0) {
+            int pop = x % 10;
+            x /= 10;
+            if (rev > INT_MAX/10 || (rev == INT_MAX / 10 && pop > 7)) return 0;
+            if (rev < INT_MIN/10 || (rev == INT_MIN / 10 && pop < -8)) return 0;
+            rev = rev * 10 + pop;
+        }
+        return rev;
+}