- function bubbleSort(arr){
- var i = j = 0;
- for(i=1; i<arr.length; i++){
- for(j=0; j<=arr.length-i; j++){
- var temp = 0;
- // ">" 从小到大排序
- // "<" 从大到小排序
- if(arr[j] > arr[j+1]){
- temp = arr[j]
- arr[j] = arr[j+1]
- arr[j+1] = temp
- }
- }
- }
- return arr
- }
- function quickSort(arr,l,r){
- if(l < r){
- var i = l, j = r, x = arr[i];
- while(i<j){
- while(i<j && arr[j]>x)
- j--;
- if(i<j)
- //这里用i++,被换过来的必然比x小,赋值后直接让i自加,不用再比较,可以提高效率
- arr[i++] = arr[j];
- while(i<j && arr[i]<x)
- i++;
- if(i<j)
- //这里用j--,被换过来的必然比x大,赋值后直接让j自减,不用再比较,可以提高效率
- arr[j--] = arr[i];
- }
- arr[i] = x;
- quickSort(arr, l, i-1);
- quickSort(arr, i+1, r);
- }
- }
- function merge(left, right) {
- var result = [],
- il = 0,
- ir = 0;
- while (il < left.length && ir < right.length) {
- if (left[il] < right[ir]) {
- result.push(left[il++]);
- } else {
- result.push(right[ir++]);
- }
- }
- while(left[il]){
- result.push(left[il++]);
- }
- while(right[ir]){
- result.push(right[ir++]);
- }
- return result;
- }
- function palindrome(str){
- // \W匹配任何非单词字符。等价于"[^A-Za-z0-9_]"。
- var re = /[\W_]/g;
- // 将字符串变成小写字符,并干掉除字母数字外的字符
- var lowRegStr = str.toLowerCase().replace(re,'');
- // 如果字符串lowRegStr的length长度为0时,字符串即是palindrome
- if(lowRegStr.length===0) return true;
- // 如果字符串的第一个和最后一个字符不相同,那么字符串就不是palindrome
- if(lowRegStr[0]!=lowRegStr[lowRegStr.length-1]) return false;
- //递归
- return palindrome(lowRegStr.slice(1,lowRegStr.length-1));
- }
- function reverseString(str){
- var tmp = '';
- for(var i=str.length-1; i>=0; i--)
- tmp += str[i];
- return tmp
- }
- function reverseString(str) {
- var arr = str.split("");
- var i = 0,
- j = arr.length - 1;
- while (i < j) {
- tmp = arr[i];
- arr[i] = arr[j];
- arr[j] = tmp;
- i++;
- j--;
- }
- return arr.join("");
- }
- function randomString(n){
- var str = 'abcdefghijklmnopqrstuvwxyz0123456789';
- var tmp = '';
- for(var i=0; i<n; i++) {
- tmp += str.charAt(Math.round(Math.random()*str.length));
- }
- return tmp;
- }
- function findMaxDuplicateChar(str) {
- if(str.length == 1) {
- return str;
- }
- var charObj = {};
- for(var i = 0; i < str.length; i++) {
- if(!charObj[str.charAt(i)]) {
- charObj[str.charAt(i)] = 1;
- } else {
- charObj[str.charAt(i)] += 1;
- }
- }
- var maxChar = '',
- maxValue = 1;
- for(var k in charObj) {
- if(charObj[k] >= maxValue) {
- maxChar = k;
- maxValue = charObj[k];
- }
- }
- return maxChar + ':' + maxValue;
- }
- function unique(arr){
- var obj = {}
- var result = []
- for(var i in arr){
- if(!obj[arr[i]]){
- obj[arr[i]] = true;
- result.push(arr[i]);
- }
- }
- return result;
- }
- function getMaxProfit(arr){
- var min = arr[0],
- max = arr[0];
- for(var i = 0; i < arr.length; i++){
- if(arr[i] < min) min = arr[i];
- if(arr[i] > max) max = arr[i];
- }
- return max - min;
- }
- function factorialize(num) {
- var result = 1;
- if(num < 0) return -1;
- if(num == 0 || num == 1) return 1;
- while(num>1) {
- result *= num--;
- }
- return result;
- }
- function factorialize(num) {
- var result = 1;
- if(num < 0) return -1;
- if(num == 0 || num == 1) return 1;
- if(num > 1) return num*factorialize(num-1);
- }
- function getfib(n){
- if(n == 0) return 0;
- if(n == 1) return 1;
- if(n > 1) return getfib(n-1) + getfib(n-2);
- }
- function fibo(len){
- var fibo = [];
- for(var i = 0; i < len; i++){
- fibo.push(getfib(i));
- }
- return fibo;
- }
- function getFibonacci(n) {
- var fibarr = [];
- var i = 0;
- while(i < n) {
- if(i <= 1) {
- fibarr.push(i);
- } else {
- fibarr.push(fibarr[i - 1] + fibarr[i - 2])
- }
- i++;
- }
- return fibarr;
- }
- function binary_search(arr, key) {
- var low = 0,
- high = arr.length - 1;
- while(low <= high){
- var mid = parseInt((high + low) / 2);
- if(key == arr[mid]){
- return mid;
- }else if(key > arr[mid]){
- low = mid + 1;
- }else if(key < arr[mid]){
- high = mid -1;
- }
- }
- return -1;
- }
- function binary_search2(arr, low, high, key) {
- if(low > high) return -1;
- var mid = parseInt((low + high)/2);
- if(key == arr[mid]) {
- return mid;
- } else if(key > arr[mid]) {
- return binary_search2(arr, mid+1, high, key);
- } else if(key < arr[mid]) {
- return binary_search2(arr, low, mid-1, key);
- }
- }
来源: http://www.tuicool.com/articles/U7VJFzM