function a() { var arr = new Array(1000000); for(var i = 0; i < arr.length;i ++) { arr[i] = i; } var start1 = new Date().getTime(); for(var i = 0; i < arr.length;i ++) { arr[i] = i+1; } var stop1 = new Date().getTime(); console.info(stop1-start1); v
一.Map,Set,Array对比: 1.增 let map = new Map(); let set = new Set(); let array = []; map.set('t',1); //Map set.add({t:1}); //Set array.push({t:1});//数组 console.info('set-map-array',set,map,array); 2.查 let map_exist = map.has('t'); let set_exist = set.has
Given an array, rotate the array to the right by k steps, where k is non-negative. 给定一个数组,并且给定一个非负数的值k, 把数组往右旋转k步,要求不返回新的数组,直接改变原数组 例子1: 给定数组: [1,2,3,4,5,6,7] 给定 k = 3 输出数组: [5,6,7,1,2,3,4] 解析: 往右旋转1步: [7,1,2,3,4,5,6] 往右旋转2步: [6,7,1,2,3,4,5] 往右旋转3步:
package test; import java.util.*; /** * Created by ming */ public class Test { public static void main(String[] args) { Set<Long> longSet=new HashSet<>(); longSet.add(1L); longSet.add(2L); List<Long> longList=new ArrayList<>(); lon
Contest time again! How excited it is to see balloons floating around. But to tell you a secret, the judges' favorite time is guessing the most popular problem. When the contest is over, they will count the balloons of each color and find the result.