堆与堆排序

原文链接：http://blog.youkuaiyun.com/morewindows/article/details/6709644

void MinHeapFixup1(int *a,int i){
    int j;
    int temp;

    j = (i - 1) / 2;
    temp = a[i];

    while(j >= 0 && i != 0){
        if(a[j] < a[i])
            break;

        a[i] = a[j];
        i = j;
        j = (i - 1) / 2;
    }
    a[i] = a[j];
}

void MinHeapFixup(int *a,int i){
    for(int j = (i - 1) / 2; j >= 0 && i != 0 && a[j] > a[i];i = j,j = (i - 1) / 2)
    swap(a[i],a[j]);
}

void MinHeapAddNum(int *a,int n,int num){
    a[n] = num;
    MinHeapFixup(a,n);
}

void MinHeapFixdown(int *a,int i,int n){
    int j = 2 * i + 1;
    int temp = a[i];

    while(j < n){
        if(j + 1 < n && a[j + 1] < a[j])
            j++;
        if(a[j] > temp)
            break;

        a[j] = temp;
        i = j;
        j = 2 * i + 1;
    }
        a[i] = temp;
}

void MinHeapFixdown2(int *a,int i,int n){
    for(int j = 2 * i + 1; j < n && i < n;i = j,j = 2 * i + 1){
        if(j + 1 < n && a[j + 1] < a[j])
            j++;

        if(a[j] > a[i])
            break;
        swap(a[j],a[i]); 
    }
}

void MinHeapDelNum(int *a,int n){
    swap(a[0],a[n - 1]);
    MinHeapFixdown(a,0,n - 1);
}

void MakeMinHeap(int *a,int n){
    for(int i = n / 2 - 1;i >= 0;i--)
        MinHeapFixdown(a,i,n);
}

void MinHeapSortToDes(int *a,int n){
    MakeMinHeap(a,n);

    for(i = n - 1;i >= 0;i--){
        swap(a[0],a[i]);
        MinHeapFixdown(a,0,i);
    }
}