sort with custom comp function

lectures/03_classes_I/README.md

@@ -144,6 +144,6 @@ bool earlier_date (const Date& a, const Date& b) {
 
 ## 3.11 Exercises
 
+- [Leetcode problem 905: Sort Array By Parity](https://leetcode.com/problems/sort-array-by-parity/). Solution: [p905_sortarraybyparity.cpp](../../leetcode/p905_sortarraybyparity.cpp)
 - [Leetcode problem 977: Squares of a Sorted Array](https://leetcode.com/problems/squares-of-a-sorted-array/). Solution: [p977_sortedsquare.cpp](../../leetcode/p977_sortedsquare.cpp)
 - [Leetcode problem 1051: Height Checker](https://leetcode.com/problems/height-checker/). Solution: [p1051_heightchecker.cpp](../../leetcode/p1051_heightchecker.cpp)
-- [Leetcode problem 1662: Check If Two String Arrays are Equivalent](https://leetcode.com/problems/check-if-two-string-arrays-are-equivalent/)

leetcode/p905_sortarraybyparity.cpp

@@ -0,0 +1,17 @@
+// the less than function
+bool comp(int A, int B){
+    if(A%2==0 && B%2!=0){
+        return true;
+    }else{
+        return false;
+    }
+}
+
+class Solution {
+public:
+
+    vector<int> sortArrayByParity(vector<int>& nums) {
+        sort(nums.begin(),nums.end(),comp);
+        return nums;
+    }
+};