Given two unsorted arrays arr1 and arr2. They may contain duplicates. For each element in arr1 count elements less than or equal to it in array arr2.
Input : arr1 = [1, 2, 3, 4, 7, 9] arr2 = [0, 1, 2, 1, 1, 4] Output : [4, 5, 5, 6, 6, 6] Input : arr1 = [5, 10, 2, 6, 1, 8, 6, 12] arr2 = [6, 5, 11, 4, 2, 3, 7] Output : [4, 6, 1, 5, 0, 6, 5, 7]
Naive Approach: Using two loops, outer loop for elements of array arr1 and inner loop for elements of array arr2. Then for each element of arr1, count elements less than or equal to it in arr2.
Time complexity: O(m * n), considering arr1 and arr2 are of sizes m and n respectively.
Efficient Approach: Sort the elements of 2nd array, i.e., array arr2. Then perform a modified binary search on array arr2. For each element x of array arr1, find the last index of the largest element smaller than or equal to x in sorted array arr2.
4 5 5 6 6 6
Time Complexity: O(mlogn + nlogn), considering arr1 and arr2 are of sizes m and n respectively.
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