leetcode

Solution to some Leetcode problems written in C++
git clone git://git.dimitrijedobrota.com/leetcode.git
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2824.cpp (728B)

      1 // Brute force
      2 class Solution {
      3   public:
      4     int countPairs(const vector<int> &nums, int target) const {
      5         const int n = size(nums);
      6         int res = 0;
      7 
      8         for (int i = 0; i < n; i++) {
      9             for (int j = 0; j < i; j++) {
     10                 res += nums[i] + nums[j] < target;
     11             }
     12         }
     13 
     14         return res;
     15     }
     16 };
     17 
     18 // Two pointer
     19 class Solution {
     20   public:
     21     int countPairs(vector<int> &nums, int target) const {
     22         int i = 0, j = size(nums) - 1;
     23         int res = 0;
     24 
     25         sort(begin(nums), end(nums));
     26         while (i < j) {
     27             if (nums[i] + nums[j] < target)
     28                 res += j - i, i++;
     29             else
     30                 j--;
     31         }
     32 
     33         return res;
     34     }
     35 };