You are given a binary string target and another string s initialized to all zeros. In one operation, you can flip all bits in the inclusive range starting from index i to n-1. The task is to determine the minimum number of operations needed to make s equal to target.
You are given the root of a binary tree and an integer distance. A pair of two different leaf nodes is considered good if the shortest path between them is less than or equal to the given distance. The task is to return the number of such good leaf node pairs in the tree.
You are given an array of distinct integers and an integer k. The game is played between the first two elements of the array. In each round, the larger integer wins and remains at position 0, while the smaller integer moves to the end of the array. The game ends when one integer wins k consecutive rounds. Your task is to return the integer that wins the game.
You are given an n x n binary grid, and in one move, you can swap any two adjacent rows. The grid is valid if all the cells above the main diagonal are zeros. Your task is to return the minimum number of swaps needed to make the grid valid, or -1 if it’s not possible.
You are given two strings s and t and a number k. Your task is to convert string s into string t using no more than k moves. In each move, you can choose an index j (1-based) from string s and shift the character at that index by i positions, where i is the current move number.
You are given a string s containing only the characters '(' and ')'. A string is considered balanced if each '(' has a matching pair of consecutive '))' and if they appear in the correct order. Your task is to return the minimum number of insertions needed to make the string balanced.