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  MCMF? solution codeforces You are given two integer arrays aa and bb (bi≠0bi≠0 and |bi|≤109|bi|≤109). Array aa is sorted in non-decreasing order. The cost of a subarray a[l:r]a[l:r] is defined as follows: If ∑j=lrbj≠0∑j=lrbj≠0, then the cost is not defined. Otherwise: Construct a bipartite flow graph with r−l+1r−l+1 vertices, labeled from ll to rr, with all vertices having bi<0bi<0 on the left and those with bi>0bi>0 on right. For each i,ji,j such that l≤i,j≤rl≤i,j≤r, bi<0bi<0 and bj>0bj>0, draw an edge from ii to jj with infinite …

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  Palindromic Indices solution codeforces You are given a palindromic string ss of length nn. You have to count the number of indices ii (1≤i≤n)(1≤i≤n) such that the string after removing sisi from ss still remains a palindrome. For example, consider ss = “aba” If we rem ove s1s1 from ss, the string becomes “ba” which is not a palindrome. If we remove s2s2 from ss, the string becomes “aa” which is a palindrome. If …

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Check if There Is a Valid Parentheses String Path solution leetcode A parentheses string is a non-empty string consisting only of ‘(‘ and ‘)’. It is valid if any of the following conditions is true: It is (). It can be written as AB (A concatenated with B), where A and B are valid parentheses strings. It can be written as (A), where A is a valid parentheses string. You are given an m x n matrix of parentheses grid. …

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Count Number of Texts solution leetcode Alice is texting Bob using her phone. The mapping of digits to letters is shown in the figure below. In order to add a letter, Alice has to press the key of the corresponding digit i times, where i is the position of the letter in the key. For example, to add the letter ‘s’, Alice has to press ‘7’ four times. …

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Count Nodes Equal to Average of Subtree solution leetcode Given the root of a binary tree, return the number of nodes where the value of the node is equal to the average of the values in its subtree. Note: The average of n elements is the sum of the n elements divided by n and rounded down to the nearest integer. A subtree of root is a tree consisting of root and all of its descendants. Count Nodes Equal …

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Largest 3-Same-Digit Number in String solution leetcode You are given a string num representing a large integer. An integer is good if it meets the following conditions: It is a substring of num with length 3. It consists of only one unique digit. Return the maximum good integer as a string or an empty string “” if no such integer exists. Note: A substring is a contiguous sequence of characters within a string. …

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 Jee, You See? solution codeforces   During their training for the ICPC competitions, team “Jee You See” stumbled upon a very basic counting problem. After many “Wrong answer” verdicts, they finally decided to give up and destroy turn-off the PC. Now they want your help in up-solving the problem. You are given 4 integers nn, ll, rr, and zz. Count the …

Jee, You See? solution codeforces- During their training for the ICPC competitions, team “Jee You See” stumbled upon a very basic counting problem. After many “Wrong answer” verdicts, they finally decided to give up and destroy turn-off the PC. Now they want your help in up-solving the problem. Read More »

 Hemose on the Tree solution codeforces   After the last regional contest, Hemose and his teammates finally qualified to the ICPC World Finals, so for this great achievement and his love of trees, he gave you this problem as the name of his team “Hemose 3al shagra” (Hemose on the tree). You are given a …

 Hemose on the Tree solution codeforces- After the last regional contest, Hemose and his teammates finally qualified to the ICPC World Finals, so for this great achievement and his love of trees, he gave you this problem as the name of his team “Hemose 3al shagra” (Hemose on the tree). Read More »

 Hemose on the Tree solution codeforces   After the last regional contest, Hemose and his teammates finally qualified to the ICPC World Finals, so for this great achievement and his love of trees, he gave you this problem as the name of his team “Hemose 3al shagra” (Hemose on the tree). You are given a …

Hemose on the Tree solution codeforces- After the last regional contest, Hemose and his teammates finally qualified to the ICPC World Finals, so for this great achievement and his love of trees, he gave you this problem as the name of his team “Hemose 3al shagra” (Hemose on the tree). Read More »

Very Suspicious solution codeforces Sehr Sus is an infinite hexagonal grid as pictured below, controlled by MennaFadali, ZerooCool and Hosssam. They love equilateral triangles and want to create nn equilateral triangles on the grid by adding some straight lines. The triangles must all be empty from the inside (in other words, no straight line or hexagon edge …

Very Suspicious solution codeforces- Sehr Sus is an infinite hexagonal grid as pictured below, controlled by MennaFadali, ZerooCool and Hosssam. Read More »