 last submission beat 100% of other submissions' runtime ||  simple and easy  solution || beginner||
IntuitionApproachComplexity
Time complexity:

Space complexity:
Code
# Intuition
<!-- Describe your first thoughts on how to solve this problem. -->

# Approach
<!-- Describe your approach to solving the problem. -->

# Complexity
- Time complexity:
<!-- Add your time complexity here, e.g. $$O(n)$$ -->

- Space complexity:
<!-- Add your space complexity here, e.g. $$O(n)$$ -->

# Code
```cpp []
class Solution {
public:
    int countPairs(vector<int>& nums, int target) {
         int n = nums.size();
         
         int count  = 0;
         for(int i =0 ;i<n ;i++){
             for(int  j = i+1 ;j<n ;j++){
            int   sum = nums[i]+  nums[j]; //calculate all the pairs sum  an then find which is less than the target  
                if(sum < target) {
                    count++; // for increasing thr count
                }
             }
         }
         return count;
    }
};
```
['C++']