(C/C++) 基本排序法

C++ Class 宣告

class Sort{
private:
    void Merge(int *arr, int front, int mid, int end);
    int Partition(int *arr, int front, int end);
public:
    void BubblesSort(int *arr, int size);
    void InsertSort(int *arr, int size);
    void MergeSort(int *arr, int front, int end);
    void QuickSort(int *arr, int front, int end);
};

排序法實現

int Sort::Partition(int *arr, int front, int end){
    int pivot = arr[end];
    int i = front;
    for(int j = front; j < end; j++){
        if(arr[j] < pivot){
            swap(arr[j], arr[i]);
            i++;
        }
    }
    swap(arr[i], arr[end]);
    return i;
}

void Sort::QuickSort(int *arr, int front, int end){
    if(front < end){
        int pivot = Partition(arr, front, end);
        QuickSort(arr, front, pivot - 1);
        QuickSort(arr, pivot + 1, end);
    }
}

void Sort::BubblesSort(int *arr, int size){
    int len = size;
    for(int i = 0; i < len; i++){
        for(int j = i + 1; j < len; j++){
            if(arr[j] < arr[i])
                swap(arr[i], arr[j]);
        }
    }
}

void Sort::InsertSort(int *arr, int size)
{
    int len = size;
    int insert = 0;
    for(int i = 1; i < len; i++){
        insert = arr[i];
        for(int j = i - 1; j >= 0; j--){
            if(insert < arr[j])
                arr[j + 1] = arr[j];
            else
                break;
        }
    }
}

void Sort::Merge(int *arr, int front, int mid, int end){
    int i, j, k;
    int n1 = mid - front + 1;
    int n2 = end - mid;
    int LeftSub[n1];
    int RightSub[n2];

    /* copy array */
    for(i = 0; i < n1; i++)
        LeftSub[i] = arr[front + i];
    for(i = 0; i < n2; i++)
        RightSub[i] = arr[mid + i + 1];

    i = 0; j = 0; k = front;
    while(i < n1 && j < n2){
        if(LeftSub[i] <= RightSub[j]){
            arr[k] = LeftSub[i];
            i++;
        }else{
            arr[k] = RightSub[j];
            j++;
        }
        k++;
    }
    while(i < n1){
        arr[k] = LeftSub[i];
        i++; k++;
    }
    while(j < n2){
        arr[k] = RightSub[j];
        j++; k++;
    }
}


void Sort::MergeSort(int *arr, int front, int end){
    if(front < end){
        int mid = (front + end) / 2;
        MergeSort(arr, front, mid);
        MergeSort(arr, mid + 1, end);
        Merge(arr, front, mid, end);
    }
}


void swap(int *a, int *b){
    int temp;
    temp = *a;
    *a = *b;
    *b = temp;
}