https://www.hackerrank.com/contests/w8/challenges/counter-game 关键是二分查找等于或最接近的小于target的数.可以使用和mid+1判断来比较~ 另有一种做法如下: http://stackoverflow.com/questions/6553970/find-the-first-element-in-an-array-that-is-greater-than-the-target #include <iostream> #inc…

在HankerRank遇到一题计算柱状图连续矩形面积的问题. 举例 hist = [3, 2, 3]. 在这个柱状图里面最大可以容纳一个high = 2 length = 3的连续矩形, 其面积 = 2*3 = 6. 按照提示需要使用stack来是时间复杂度保持在O(n). 搜索提示和代码, 把自己的理解描述如下: 加入数组是升序的 hist = [1, 2, 3] 因为数组是升序的, 所以每一个都会和之后的 high 形成更大的连续面积. 也因为数组是升序的, 所以每一个都会和之前的 high…

Steve has a string of lowercase characters in range ascii[‘a’..’z’]. He wants to reduce the string to its shortest length by doing a series of operations. In each operation he selects a pair of adjacent lowercase letters that match, and he deletes th…