算法设计题--2

six

顺序表中实现二分查找

struct record
{
    int key;
    int others;
};
int bisearch(struct record r[],int k)
{
    int low = 0,mid,high = n-1;
    while(low<=high)
    {
        mid(low+high)/2;
        if(r[mid].key==k) return (mid+1);
        else if(r[mid].key>k) high = mid-1;
        else low = mid+1;
    }
    return 0;
}

判断二叉树是否为二叉排序树

int minnum = -32768,flag = 1;
typedef struct node
{
    int key;
    struct node *lchild,*rchild;
}bitree;
void inoeder(bitree *bt)
{
    if(bt!=0)
    {
        inoeder(bt->lchild);
        if(minnum>bt->key) flag = 0;
        minnum = bt->key;
        inoeder(bt->rchild);
    }

}

链式结构上直接插入排序

void straightinsertsort(lklist *&head)
{
    lklist *s,*p,*q;
    int t;
    if(head==0||head->next==0) return;
    else for(q=head,p=head->next;p!=0;p=q->next)
    {
        for(s=head;s!=q->next;s=s->next) if(s->data>p->data) break;
        if(s==q->next) q=p;
        else{
            q->next=p->next;
            p->next=s->next;
            s->next=p;
            t=p->data;
            p->data=s->data;
            s->data=t;
        }
    }
}

seven

链式结构实现简单选择排序

void simpleselectsorlklist(lklist *&head)
{
    lklist *p,*q,*s;
    int min,t;
    if(head==0||head->next==0) return;
    for(q=head;q!=0;q=q->next)
    {
        min=q->data;
        s=q;
        for(p=q->next;p!=0;p->p->next)
            if(min>p->data){
                min = p->data;
                s=p;
            }
        if(s!=q)
        {
            t=s->data;
            s->data=q->data;
            q->data=t;
        }
    }
}

顺序表上实现求子串的算法

void substring(char s[],long start,long count,char t[])
{
    long i,j,length = strlen(s);
    if(start<1||start>length) cout<<"error\n";
    else if(start+count-1>length) cout<<"error\n"
    else{
        for (i=start-1,j=0;i<start+cout-1;i++,j++)
        {
            t[j]=s[i];
            t[j]='\0';
        }
    }
}

求节点在二叉排序树中层次的算法

int lev=0;
typedef struct node
{
    int key;
    struct node *lchild,*rchild;
}bitree;

void level(bitree *bt,int x)
{
    if(bt!=0)
    {
        lev++;
        if(bt->key==x) return;
        else if(bt->key>x) level(bt->lchild,x);
        else level(bt->rchild,x);
    }
}

eight

求链式结构上二叉树节点个数

void countnode(bitree *bt,int &count)
{
    if(bt!=0)
    {
        count++;
        countnode(bt->lchild,count);
        countnode(bt->rchild,count);
    }
}

设计将无向图的邻接矩阵变为邻接表的算法

typedef struct
{
    int vertex[m];
    int edge[m][m];
}gadjmatix;
typedef struct node1
{
    int info;
    int adjvertex;
    struct node1 *nextarc;
}glinklisnode;
typedef struct node2
{
    int vertexinfo;
    glinklisnode *firstarc;
}glinkheadnode;

void adjmatrixtoadilist(gadjmatix g1[],glinkheadnode g2[])
{
    int i,j;
    glinklisnode *p;
    for(i=0;i<=n;i++)
    {
        g2[i].firstarc=0;
    }
    for(i=0;i<=n;i++)
    {
        for(j=0;j<=n-1;j++)
        {
            if(g1.edge[i][j]==1)
            {
                p=(glinklisnode *)malloc(sizeof(glinklisnode));
                p->adjvertex=j;
                p->nextarc=g[i].firstarc;
                g[i].firstarc=p;
                p=(glinklisnode *)malloc(sizeof(glinklisnode));
                p->adjvertex=i;
                p->next=g[i].firstarc;
                g[i].firstarc=p;
            }
        }
    }
}

nine

求二叉树上所有节点之和

void sum(bitree *bt,int &s)
{
    if(bt!=0)
    {
        s=s+bt->data;
        sum(bt->lchild,s);
        sum(bt->rchild,s);
    }
}

设计将所有奇数移到偶数之前的算法

void quickpss(int r[],int s,int t)
{
    while(i<j)
    {
        while(i<j&&r[j]%2==0) j=j-1;
        if(i<j)
        {
            r[i]=r[j];
            i=i+1;
        }
        while(i<j&&r[j]%2!=0) i=i+1;
        {
            if(i<j)
            {
                r[j]=r[i];
                j=j-1;
            }
        }
    }
}

判断链表是否递增

int isriselk(lklist *head)
{
    if(head==0||head->next==0)
    {
        return 1;
    }else{
        for(q=head,p=head->next;p!=0;q=p,p=p->next)
        {
            if(q->data>p->data)
                return 0;
        }
    }
    return 1;
}

ten

链式结构上合并排序

void mergelklist(lklist *ha,lklist *hb,lklist *&hc)
{
    lklist *s = hc = 0;
    while(ha!=0&&hb!=0)
    {
        if(ha->data<hb->data)
        {
            if(s==0) hc=s=ha;
            else{
                s->next = ha;
                ha=ha->next;
            }
        }else{
            f(s==0) hc=s=hb;
            else{
                s->next = hb;
                hb=hb->next;
            }
        }
    }
    if(ha==0){
        s->next = hb;
    }else{
        s->next=ha;
    }
}

二叉排序树上查找节点 x

bitree *bisearch(bitree *t,int key)
{
    bitree *p = t;
    while(p!=0)
    {
        if(p->key==key) return p;
        else if(p->key>key) p=p->lchild;
        else p=p->rchild;
    }
    return 0;
}

设计算法将关键序列调整为堆

void adjustheap(int r[],int n)
{
    int j=n,i=j/2;temp=r[j-1];
    while(i>=1)
        if(temp>=r[i-1]) break;
        else{
            r[j-1]=r[i-1];
            j=i;
            i=i/2;
        }
        r[j-1]=temp;
}