Suppose there are n bikes and each can cover 100 km when they are fully fueled. We have to find the maximum amount of distance we can go using these n bikes. Here we can assume that all bikes are similar and a bike consumes 1 litre of fuel to cover 1 km distance. So, if n bikes start from same point and run parallel, we can go only 100 km, in this case our target is to cover maximum distance, with minimum fuel. And minimum wastage of fuel means minimum number of bikes used. If the bikes run serially, ... Read More

Suppose we have a string we have to return the longest possible substring that has exactly k number of unique characters, if there are more than one substring of longest possible length, return any of them.So, if the input is like s = "ppqprqtqtqt", k = 3, then the output will be rqtqtqt as that has length 7.To solve this, we will follow these steps −N := 26Define a function is_ok() . This will take count, kval := 0for i in range 0 to N, doif count[i] > 0, thenval := val + 1return true when (k >= val)From the ... Read More

Suppose we have an array A of n different numbers and another positive integer K, we have to find the longest sub-sequence in the array having Least Common Multiple (LCM) at most K. After than return the LCM and the length of the sub-sequence, following the indexes (starting from 0) of the elements of the obtained sub-sequence. Otherwise, return -1.So, if the input is like A = [3, 4, 5, 6], K = 20, then the output will be LCM = 12, Length = 3, Indexes = [0, 1, 3]To solve this, we will follow these steps −n := size ... Read More

Suppose we have a given string, we have to find the largest sub-string which is a prefix, a suffix and a sub-string of that given string. If there is no such substring, then return -1.So, if the input is like "languagepythonlanguageinterestinglanguage", then the output will be "language"To solve this, we will follow these steps −Define a function get_lps() . This will take stringn := size of stringlong_pref_suff := an array of size n, and fill with 0size := 0, long_pref_suff[0] := 0, i := 1while i < n is non-zero, doif string[i] is same as string[size], thensize := size + ... Read More

Suppose we have an array A of n numbers, where A[i] indicates the number of distinct characters in the prefix of length (i + 1) of a string s, we have to find the lexicographically smallest string that satisfies the given prefix array. All characters will be lowercase English alphabets [a-z]. If there is no such string then return -1.So, if the input is like A = [1, 1, 2, 3, 4], then the output will be aabcd as prefix[0] has 1 distinct character, prefix[1] has 1 distinct character, prefix[2] has 2 distinct characters, prefix[3] has 3 distinct characters, prefix[4] ... Read More

Suppose we have a string S; we have to find the lexicographically largest palindromic subsequence of that string.So, if the input is like "tutorialspointtutorial", then the output will be "uu"To solve this, we will follow these steps −ans := blank stringmax_val := s[0]for i in range 1 to size of s, domax_val := maximum of max_val, s[i]for i in range 0 to size of s, doif s[i] is same as max_val, thenans := ans + s[i]return ansExample Let us see the following implementation to get better understanding − Live Demodef largest_palindromic_substr(s):    ans = ""    max_val = s[0]    for i ... Read More

Suppose we have a binary matrix, we have to find the largest rectangle of all 1's in that given matrix. The rectangle can be built by swapping or exchanging any pair of columns of that matrix.So, if the input is like100101001111010then the output will be the 6 in this case. The rectangle can be generating by exchanging column 1 with 3. The matrix after exchanging will be −001100011110110To solve this, we will follow these steps −row := size of matcol := size of mat[0]temp := a matrix of order (row + 1) x (col + 1), and fill with 0for ... Read More

Suppose we have a given Binary Tree; we have to find the size of largest Perfect sub-tree in that given Binary Tree. As we know the perfect binary tree is a binary tree in which all internal nodes have two children and all leaves are at the identical level.So, if the input is likethen the output will be 3, and the subtree isTo solve this, we will follow these steps −Define one block called RetType, this will hold isPerfect, height and rootTree, they are all initially 0Define a function called get_prefect_subtree(), this takes rootr_type := a new RetTypeif root is ... Read More

Suppose we have an array A with n numbers and another input K, we have to find the index which will be the last to be reduced to zero after performing a given operation. The operation is explained as follows −Starting from A[0] to A[N – 1], update each element as A[i] = A[i] – K. Now, if A[i] < K then put A[i] = 0 and no further operation will be done on A[i] once it is 0.We have to repeat the operation until all of the elements are reduced to 0. And return the index which will be ... Read More

Suppose we have an array, we have to find an element before which all elements are less than it, and after which all are greater than it. Finally, return the index of the element, if there is no such element, then return -1.So, if the input is like A - [6, 2, 5, 4, 7, 9, 11, 8, 10], then the output will be 4.To solve this, we will follow these steps −n := size of arrmaximum_left := an array of size nmaximum_left[0] := -infinityfor i in range 1 to n, domaximum_left[i] := maximum of maximum_left[i-1], arr[i-1]minimum_right := infinityfor i ... Read More