二分查找、快排、堆排

算法思想不做赘述。
二分查找:

int binarySearch(int *a,int len,int key){
    int left=0,right=len-1;
    while(left<==right){
        int mid=left+(right-left)/2;
        if(a[mid]==key)
            return mid;
        else if(a[mid]<key)
            left=mid+1;
        else
            right=mid-1;
    }
    return -1;
}

快排:

void quickSort(int *a,int left,int right){
    int i,j.mddle;
    i=left,j=right;
    middle=a[left+(right-left)/2];
    while(i<j){
        while(a[i]<middle&&i<right)
            i++;
        while(a[j]>middle&&j>left)
            j--;
        if(i<=j)
            swap(a[i++],a[j--]);
    }
    if(i<right)
        quickSort(a,i,right);
    if(j>left)
        quickSort(a,left,j);
}

堆排:

void maxheap_down(int *a,int start,int end){
    int c=start;//当前节点位置
    int l=2*c+1;//左孩子
    for(;l<=end;c=l,l=2*l+1){
    if(l<end&&a[l]<a[l+1])
        l++;
    if(a[c]>a[l])
        break;
    else
        swap(a[c],a[l]);
    }
}
void heap_sort_asc(int *a,int n){
    int i;
    for(i=n/2-1;i>=0;i--)
        maxheap_down(a,i,n-1);
    for(i=n-1;i>0;i--){
        swap(a[0],a[i]);
        maxheap_down(a,0,i-1);
    }
}

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转载自blog.csdn.net/haoshan4783/article/details/84581097
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