Catalog

One 、 Concept

Two 、 Code

One 、 Concept

A sort of permutation , Recursive implementation , The core is to find a value at will , And put the smaller one in front , Bigger ones in the back , Go and look for ：

1. Record pivot = arr[i];

2. Find the first less than or equal to from back to front pivot Value , Stop at the low value arr[j] The location of , be pivot Corresponding position arr[i] The value of is replaced by this small value ;

3. Find the first greater than or equal to pivot Value , Stop at high value arr[i] The location of , Then the small value arr[j] By this big value arr[i] replace ;

4. repeat 2 and 3, if i >= j, It means to use pivot The quick sort of this value is finished , And arr[i]=pivot（i It's changing ）;

5. Recursive interval