Given an array A of non-negative integers, half of the integers in A are odd, and half of the integers are even. Sort the array so that whenever A[i] is odd, i is odd; and whenever A[i] is even, i is even. You may return any answer array that satisfi…
奇偶排序法的思路是在数组中重复两趟扫描.第一趟扫描选择所有的数据项对,a[j]和a[j+1],j是奇数(j=1, 3, 5……).如果它们的关键字的值次序颠倒,就交换它们.第二趟扫描对所有的偶数数据项进行同样的操作(j=2, 4,6……).重复进行这样两趟的排序直到数组全部有序. public static void oddEvenSort(int[] arr){ int len = arr.length; int groupNumber = (int) Math.ceil((double)le…
order by order by 会对输入做全局排序,因此只有一个reducer(多个reducer无法保证全局有序)只有一个reducer,会导致当输入规模较大时,需要较长的计算时间. set hive.mapred.mode=nonstrict; (default value / 默认值) set hive.mapred.mode=strict; order by 和数据库中的Order by 功能一致,按照某一项 & 几项 排序输出. 与数据库中 order by 的区别在于在hive.…