adding one more leetcode problem

lectures/03_classes_I/README.md

@@ -144,6 +144,6 @@ bool earlier_date (const Date& a, const Date& b) {
 
 ## 3.11 Exercises
 
-- [Leetcode problem 1051: Height Checker](https://leetcode.com/problems/height-checker/) Solution: [p1051_heightchecker.cpp](../../leetcode/p1051_heightchecker.cpp)
-- [Leetcode problem 211: Design Add and Search Words Data Structure](https://leetcode.com/problems/design-add-and-search-words-data-structure/)
+- [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/p977_sortedsquare.cpp

@@ -0,0 +1,13 @@
+class Solution {
+public:
+    vector<int> sortedSquares(vector<int>& nums) {
+        int size = nums.size();
+        vector<int> squares;
+        // create the squares vector
+        for(int i=0;i<size;i++){
+            squares.push_back(nums[i]*nums[i]);
+        }
+        sort(squares.begin(),squares.end());
+        return squares;
+    }
+};