Simple 2 pointer approach || C++
Intuition\n Describe your first thoughts on how to solve this problem. \n\n# Approach\n Describe your approach to solving the problem. \n\n# Complexity\n- Time 
# Intuition\n<!-- Describe your first thoughts on how to solve this problem. -->\n\n# Approach\n<!-- Describe your approach to solving the problem. -->\n\n# Complexity\n- Time complexity:\n<!-- Add your time complexity here, e.g. $$O(n)$$ -->\n\n- Space complexity:\n<!-- Add your space complexity here, e.g. $$O(n)$$ -->\n\n# Code\n```\nclass Solution {\npublic:\n    int countPairs(vector<int>& nums, int target) {\n        int n = nums.size();\n        sort(nums.begin(), nums.end()); \n        \n        int count = 0;\n        int left = 0, right = n - 1;\n        \n        while (left < right) {\n            if (nums[left] + nums[right] < target) {\n              \n                count += right - left;\n                left++;\n            } else {\n             \n                right--;\n            }\n        }\n        \n        return count;\n    }\n};\n```
['C++']