排序算法（冒泡插入快速归并）java

系统管理员 2022-07-24 12:01 193阅读 0赞

1.  冒泡

public static void bubble(int[]array){
            for(int i=0; i<array.length-1; i++){
                for(int j=i+1; j<array.length; j++){
                    if(array[i] > array[j]){
                        int tmp;
                        tmp = array[j];
                        array[j] = array[i];
                        array[i] = tmp;
                    }
                }
            }
        }

1.  插入

public static void insert(int[]array){
            int i,j;
            int currentValue;
            int position;
            for(i=1;i<array.length;i++)
            {
                currentValue = array[i];//存储当前的值
                position = i;
                for(j=i-1;j>=0;j--){
                    if(array[j]>currentValue){
                        array[j+1]=array[j];
                        position--;
                    }else{
                        break;
                    }
                }
                array[position] = currentValue;
            }
        }

1.  快速

public static void quickSort(int[] array){
            if(array.length>0)
                quick(array,0,array.length-1);
        }
        public static void quick(int[] array, int low, int high){
            if(low < high){
                int middle = getMiddle(array,low,high);
                quick(array,low,middle-1);
                quick(array,middle+1,high);
            }
        }
        public static int getMiddle(int[] array, int low, int high){
            int tmp = array[low];//数组的第一个作为中轴 
            while(low < high){
                while(low<high && array[high]>=tmp){
                    high--;
                }
                array[low] = array[high];
                while(low<high && array[low]<=tmp){
                    low++;
                }
                array[high] = array[low];
            }
            array[low] = tmp;
            return low;
        }

1.  归并

public static void mergeSort(int[] array, int low,int high){
             int middle = (low+high)/2;
                 if(low < high){
                     mergeSort(array,low,middle);
                     mergeSort(array,middle+1,high);
                     merge(array,low,middle,high);
                 }
        }
        public static void merge(int[] array, int low,int midle, int high){
            int[] tmp = new int[high+1-low];
            int middle = (low+high)/2;
            int i = low;
            int j = middle + 1;
            int k = 0;
            while(i<=middle&&j<=high){
                if(array[i]<array[j]){
                    tmp[k++] = array[i++];
                }else{
                    tmp[k++] = array[j++];
                }
            }
            if(i<=middle){
                System.arraycopy(array, i, tmp, k, middle+1-i);
            }
            if(j<=high){
                System.arraycopy(array, j, tmp, k+middle+1-i, high+1-j);
            }
            System.arraycopy(tmp, 0, array, low, tmp.length);
        }