Given an unsorted array, find the minimum difference between any pair in given array.

• At first sort the array. Then all the minimum differences will occur amoung the pairs of consecutive elements.
• Then iterate over the sorted array keeping track of the current minimum difference.

There is the answer.
Time Complextiy: O(nlogn) (sorting) + O(n) (iteration) = O(nlogn).
Optimal implementation wont use any extra space.

int solve(){
  int nums[5] = {2,4,5,9,7};
  sort(nums, nums+5);
  int minDiff = INT_MAX;
  for(ll i = 1; i < 5; i++)
    minDiff = min(minDiff, nums[i]-nums[i-1]);
  return minDiff;
}