假设要在足够多的会场里安排一批活动，并希望使用尽可能少的会场。设计一个有效的贪心算法来进行安排。试编程实现对于给定的k个待安排活动，计算使用的最少会场。输入数据中，第一行是k的值，接下来的k行中，每行有2个正整数，分别表示k个待安排活动的开始时间和结束时间，时间以0点开始的分钟计。输出为最少的会场数。-Assume it to be enough room in the arrangements in a number of activities and want to use the venue as small as possible. Design an efficient greedy algorithm to carry out the arrangements. Test Programming k for a given month to be arranged activities, calculated using the minimum of the venue. Input data, the first line is the value of k, the next k lines, each line has two positive integers, respectively, k a question that the activities arranged by the start time and end time, time to the beginning of 0:00 minutes. Output for at least a few of the venue.