简单排序:归并排序

    public void mergeSort(int[] array){        int temp = array.length/2;                if(temp == 0){            return;        }                int[] a = new int[temp];        int[] b = new int[array.length - temp];                for(int i=0;i<temp;i++){            a[i] = array[i];        }                for(int i=0;i<array.length - temp;i++){            b[i] = array[temp + i];        }                if(a.length != 1){            this.mergeSort(a);        }        if(b.length != 1){            this.mergeSort(b);        }                int aIndex = 0;        int bIndex = 0;        int arrayIndex = 0;                while(aIndex != a.length && bIndex != b.length){            if(a[aIndex] > b[bIndex]){                array[arrayIndex++] = b[bIndex++];                continue;            }else if(a[aIndex] < b[bIndex]){                array[arrayIndex++] = a[aIndex++];                continue;            }else{                array[arrayIndex++] = a[aIndex++];                array[arrayIndex++] = b[bIndex++];            }        }                while(bIndex < b.length){            array[arrayIndex++] = b[bIndex++];        }                while(aIndex < a.length){            array[arrayIndex++] = a[aIndex++];        }    }

效率:
由于需要一个被排序数组等大小的数组来辅助排序,空间复杂度比较高,时间复杂度为:O(N*logN)