//快速排序
function quickSort(arr){if(arr.length <= 1){return arr;}var left = [], right = [];var midpos = Math.floor(arr.length/2),mid = arr.splice(mid, 1)[0];for(var i = 0; i < arr.length; i++){if(arr[i] < mid){left.push(arr[i]);}else{right.push(arr[i]);}}return quickSort(left).concat([mid], quickSort(right));
}
quickSort([12,54,1,25,67,41,12]);

//插入排序
function insert(arr){var i, j, tmp;for(i = 0; i < arr.length; i++){tmp = arr[i];for(j = i; j >= 0; j--){if(arr[j - 1] > tmp){arr[j] = arr[j - 1];}else{arr[j] = tmp;break;}}}return arr;
}
insert([12,54,1,25,67,41,12]);

//选择排序
function checked(arr){var i,j,tmp,minindex,minvalue;for(i = 0; i < arr.length - 1; i++){minindex = i;minvalue = arr[minindex];for(j = i + 1; j < arr.length; j++){if(arr[j] < minvalue ){minindex = j;minvalue = arr[minindex];}}tmp = arr[i];arr[i] = arr[minindex];arr[minindex] = tmp;}return arr;
}
checked([12,54,1,25,67,41,12]);

//归并排序
function meger(left, right){var tmp = [];while(left.length && right.length){if(left[0] < right[0]){tmp.push(left.shift());}else{tmp.push(right.shift());}}return tmp.concat(left, right);
}
function megerSort(arr){if(arr.length === 1){return arr;}var left = [], right = [], mid;mid = Math.floor(arr.length / 2);left = arr.slice(0, mid);right = arr.slice(mid);return meger(megerSort(left), megerSort(right));
}
megerSort([12,54,1,25,67,41,12]);

//冒泡排序1
function maopao1(arr){var i,j,tmp;for(i = arr.length; i >= 0; i--){for(j = 0; j < i; j++){if(arr[j] < arr[j - 1]){tmp = arr[j - 1];arr[j - 1] = arr[j];arr[j] = tmp;}}}return arr;
}
maopao1([12,54,1,25,67,41,12]);

function maopao2(arr){var i,j,tmp;for(i = 0; i < arr.length; i++){for(j = 0; j < arr.length - i; j++){if(arr[j] < arr[j - 1]){tmp = arr[j];arr[j]= arr[j - 1];arr[j - 1] = tmp;}}}return arr;
}
maopao2([12,54,1,25,67,41,12]);

//冒泡排序3
function bullSort(arr){var temp;for(var i = 0; i < arr.length; i++){for(var j = arr.length-1;j > i;j--){if(arr[j] < arr[j-1]){temp = arr[j];arr[j] = arr[j-1];arr[j - 1] = temp;}}}return arr;
}
bullSort([12,54,1,25,67,41,12]);

//查找数组中出现次数最多的数字
function getCount(arr){var i,j,maxnum,maxvalue = 0,obj = {};for(i = 0; i < arr.length; i++){if(!obj[arr[i]]){obj[arr[i]] = 1;}else{obj[arr[i]] += 1;}}console.log(obj);for( j in obj){if(obj[j] > maxvalue){maxnum = j;maxvalue = obj[maxnum];}}return maxnum + " : " + maxvalue;
}
getCount([12,54,12,54,79,11,12]);

//数组中的最大最小值的差值
function maxMin(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;
}
maxMin([12,54,79,84,11,52]);

//反转字符串1
function reverseStr(str){var newstr = '';for(var i = str.length - 1; i >= 0; i--){newstr += str[i];}return newstr;
}
reverseStr('abcdefghijklmnopqrstuvwxyz0123456789');

//反转字符串2
function reverseStr(str){var newstr = str.split(''), result = [], len = newstr.length;for(var i = 0; i < len; i++){result[(len - 1) - i] = newstr[i];}return result.join('');
}
reverseStr('abcdefghijklmnopqrstuvwxyz0123456789');

//反转字符串3
function reverseStr2(str){var newstr = str.split('');tmp,i = 0,j = newstr.length - 1;while(i < j){tmp = newstr[i];newstr[i] = newstr[j];newstr[j] = tmp;}return newstr.join('');
}
reverseStr('abcdefghijklmnopqrstuvwxyz0123456789');

//生成指定长度的字符串
function getStr(str, count){var newstr = '';for(var i = 0; i < count; i++){newstr += str.charAt(Math.floor(Math.random() * str.length));}return newstr;
}
getStr('abcdefghijklmnopqrstuvwxyz0123456789', 10);

//对象形式去重
function delMore(arr){var i, obj = {}, result = [];for(i = 0; i < arr.length; i++){if(!obj[arr[i]]){obj[arr[i]] = true;result.push(arr[i]);}}return result;
}
delMore([12,54,12,54,79,11,12]);

//选择排序方法去重
function insertMore(arr){var len = arr.length,newstr = [];for(var i = 0; i < len; i++){for(var j = i + 1; j < len; j++){if(arr[i] == arr[j]){++i;}}newstr.push(arr[i]);}return newstr;
}
insertMore([12,54,12,54,79,11,12]);