排序搜索算法建议工具
工具地址：visualgo.net/zh
一、冒泡排序
<script type="text/javascript">
function arrSort( arr ){
for(let i=0;i<arr.length-1;i++){
for(let j=0;j<arr.length-1-i;j++){
if( arr[j] > arr[j+1]){
let temp = arr[j];
arr[j] = arr[j + 1];
arr[j + 1] = temp;
}
}
}
return arr;
}
let arr = [29,10,14,37,14];
console.log( arrSort( arr ) );
</script>
二、选择排序
<script type="text/javascript">
function sortMin( arr ){
let indexMin = 0;
for( let i=0;i<arr.length-1;i++){
indexMin = i;
for( let j=i+1;j<arr.length;j++){
if( arr[j] < arr[indexMin] ){
indexMin = j;
}
}
let temp = arr[i];
arr[i] = arr[indexMin];
arr[indexMin] = temp;
}
return arr;
}
let arr = [29,10,14,37,14];
console.log( sortMin(arr) );
</script>
三、插入排序
<script type="text/javascript">
function insertSort( arr ){
let len = arr.length;
for(let i=1;i<len;i++){
let temp = arr[i];
let j = i-1;//默认已排序的元素
//在已经排序好的队列进行从后到前的扫描
while( j>=0 && arr[j] > temp ){
//已排序的元素大于新元素，将该元素移动到下一个位置
arr[j+1] = arr[j];
j--;
}
arr[j+1] = temp;
}
return arr;
}
let arr = [5,3,4,2,1];
console.log( insertSort(arr) );
</script>
四、归并排序
<script type="text/javascript">
let arr = [8,4,5,7,1,3,6,2];
function mergeSort( arr ){
//视频课程：https://www.xuexiluxian.cn/course/detail/8429c57c800544f6b49fe73f9aae21de
if( arr.length < 2 ) return arr;
let mid = Math.floor( arr.length/2 );
let merge = function(leftArr,rightArr){
console.log( leftArr,rightArr );
let resultArr = [];
while( leftArr.length && rightArr.length ){
resultArr.push( leftArr[0] <= rightArr[0] ? leftArr.shift() : rightArr.shift() )
}
return resultArr.concat(leftArr).concat(rightArr);
}
return merge(
mergeSort(arr.slice(0,mid)),
mergeSort(arr.slice(mid))
);
}
console.log( mergeSort(arr) );
</script>
五、快速排序
<script type="text/javascript">
let arr = [29,10,14,37,4];
function quickSort( arr ){
if( arr.length <=1 ) return arr;
let mid = Math.floor( arr.length/2 );
let pivot = arr.splice(mid,1)[0];
let left =[];
let right = [];
for( let i=0;i<arr.length;i++){
if( arr[i] <pivot ){
left.push( arr[i] );
}else{
right.push( arr[i] );
}
}
return quickSort(left).concat([pivot],quickSort(right));
}
console.log( quickSort(arr) );
</script>
六、二分搜索
<script type="text/javascript">
let arr = [1,2,3,4,5,6,7];
let target = 6;
//视频课程：https://www.xuexiluxian.cn/course/detail/8429c57c800544f6b49fe73f9aae21de
function search( arr , target ){
let conut = 1;
let start = 0;
let end = arr.length-1;
while( start<=end ){
//取出中间值
let middle = Math.floor( (start+end)/2 );
let guess = arr[middle];
//如果中间 == 目标值
console.log( conut );
if( guess== target ){
return middle;//返回位置
}
if( guess > target ){
end = middle;
}
if( guess < target ){
start = middle + 1;
}
conut++;
}
return -1;
}
console.log( search( arr , target) );
</script>
