最近的笔试题

1、顺序表的就地逆置 

编写一个函数，实现顺序表的就地逆置，也就是说利用原表的存储空间将顺序表(a1,a2...an)逆置为(an,an-1...a2,a1)。

#include <iostream>
#include <stdio.h>
#include <stdlib.h>
using namespace std;
//线性表的动态顺序存储结构
typedef int DataType;   /*数据类型*/
typedef int ElemType;   /*元素类型*/

#define LIST_INIT_SIZE 100  //线性表存储空间的初始分配量
#define LISTINCREMENT 10    //线性表存储空间的分配增量
typedef struct
{
    ElemType *elem; //存储空间基址
    int length;     //当前长度
    int listsize;   //当前分配的存储容量
}SqList;

void InitList(SqList *L)
//初始化
{
    L->elem = (ElemType *)malloc(LIST_INIT_SIZE*sizeof(ElemType));//分配空间
    L->length = 0;                   //空表的长度为0
    L->listsize = LIST_INIT_SIZE;    //初始容量
}

void CreateList(SqList *L)
{
    InitList(L);
    int i;
    for(i = 0; ; i ++)
    {
        scanf("%d", &L->elem[i]);
        if(L->elem[i]==-1)
            break;
        L->length++;
    }
}

void InsertList(SqList *L, int e)
{
    int i;
    for(i = L->length-1; L->elem[i] > e; i--)               //从顺序表最后一位开始，将所有大于e的元素向后移动
    {
        L->elem[i+1] = L->elem[i];
    }
    L->elem[i] = e;

    L->length++;
}

void ReverseList(SqList *L)
{
    int i, temp;
    int n = L->length;

    for(i = 0; i < n/2; i ++)
    {
        temp = L->elem[i];
        L->elem[i] = L->elem[n-1-i];
        L->elem[n-1-i] = temp;
    }
}
void ListTraverse(SqList *L)
{
    int n = L->length, i;

    for(i = 0; i < n-1; i++)
        printf("%d ", L->elem[i]);
    printf("%d
",L->elem[n-1]);
}

int main()
{
    SqList L;
    CreateList(&L);
    ReverseList(&L);
    ListTraverse(&L);
    return 0;
}

2、删除线性表中多余的元素

#include <iostream>
#include<stdio.h>
#include<stdlib.h>
#define OK 1
#define ERROR 0
using namespace std;
//采用的是线性表，单链表作为存储结构，在每一次的
//比较是否与之前的元素是否相等，遍历一次链表时间复杂度O（n）
typedef int ElemType;
typedef int Status;
typedef struct Node
{
    ElemType data;
    struct Node * next;
}Node,*LinkList;

//单链表的初始化
Status InitLinkList(LinkList * L)
{
    (*L)=(LinkList)malloc(sizeof(Node));
    if((*L)==NULL)
    {
        //printf("内存分配失败！
");
        return 0;
    }
    (*L)->next=NULL;
    return OK;
}

//单链表的建立
Status Create(LinkList * L,int n)
{
    LinkList P,Q;
    ElemType Elem;
    Q=(*L);
    //printf("请按递增顺序输入元素：
");
    for(int i=0;i<n;i++)
    {
        P=(LinkList)malloc(sizeof(Node));
        scanf("%d",&Elem);
        P->data=Elem;
        Q->next=P;
        Q=P;
    }
    P->next=NULL;
    return OK;
}

//删除结点
Status Delete(LinkList * L,int Location)
{
    LinkList Q,P;
    int count=0;
    int k=Location+1;
    Q=(*L);
    P=(*L)->next;
    while(P->next)
    {
        Q=Q->next;
        P=P->next;
        count++;
        if(count==Location)
        {
            Q->next=P->next;
        }
    }
    return OK;
}

//定位删除结点的位置并删除
Status Locate(LinkList * L)
{
    LinkList First,Second;
    int count=1;
    First=(*L)->next;
    Second=(*L)->next->next;
    while(Second)
    {
        if(First->data==Second->data)
        {
            Delete(L,count);
            Second=Second->next;
        }
        else
        {
            count++;
            First=First->next;
            Second=Second->next;
        }

    }
    return OK;
}

void Print(LinkList * L)
{
    LinkList P;
    P=(*L)->next;
    while(P)
    {
        printf("%d ",P->data);
        P=P->next;
    }
    printf("
");
}

int main()
{
    LinkList L;
    int Number;
    InitLinkList(&L);
    //printf("请输入元素个数：
");
    scanf("%d",&Number);
    Create(&L,Number);
    //printf("输出链表：
");
    //Print(&L);
    Locate(&L);
    //printf("输出去掉相同元素后链表：
");
    Print(&L);
    return 0;
}

3、表达式括号匹配

#include<stdio.h>
#include<malloc.h>
#include<string.h>
#define STACK_INIT_SIZE 10
#define STACK_GROW_SIZE 5
#define ELEMTYPE char
#define OK 1
#define ERROR 0
typedef struct { /*建立一个栈的首结点*/
    ELEMTYPE * base;
    ELEMTYPE * top;
    int stacksize;
} SpStack;
int InitStack(SpStack *s) { /*建立空的栈并返回首地址*/
    s->base=((ELEMTYPE*)malloc(STACK_INIT_SIZE*sizeof(ELEMTYPE)));
    if (!s->base) return ERROR;
    s->top=s->base;
    s->stacksize=STACK_INIT_SIZE;
    return OK;
}
int StackEmpty(SpStack *s) { /*判断栈是否为空*/
    if (s->top==s->base) return OK;
    else                 return ERROR;
}
int Push(SpStack *s,ELEMTYPE e) { /*往栈顶插入元素即进栈*/
    if (s->top-s->base>=s->stacksize) { /*判断是否栈满*/
        s->base=((ELEMTYPE*)realloc(s->base,(s->stacksize+STACK_GROW_SIZE)*sizeof(ELEMTYPE)));
        if (!s->base) return ERROR;
        s->stacksize+=STACK_GROW_SIZE;
        s->top=s->base+s->stacksize;
    }
    *s->top++=e;
    return OK;
}
int Pop(SpStack *s,ELEMTYPE *e) { /*让栈顶元素依次输出即出栈*/
    if (StackEmpty(s)) return ERROR;
    *e=*(--s->top);
    return OK;
}
int Comp(ELEMTYPE a,ELEMTYPE b) {
    if ((a=='('&&b!=')')
      ||(a=='['&&b!=']')
      ||(a=='{'&&b!='}')) {
        return ERROR;
    } else return OK;
}
int Count(SpStack *s) {
    ELEMTYPE e[STACK_INIT_SIZE*2];
    ELEMTYPE e1;
    int i;

    InitStack(s);
    fgets(e,STACK_INIT_SIZE*2,stdin);
    if ('
'==e[strlen(e)-1]) e[strlen(e)-1]=0;
    //printf("%s
",e);
    for (i=0;e[i]!='';i++) {
        switch (e[i]) {
        case '(':
        case '[':
        case '{':
            Push(s,e[i]);
            break;
        case ')':
        case ']':
        case '}':
            if (StackEmpty(s)) {
                    printf("ERROR
");
                //printf("%*s↖右括号多余
",i+1,"");
                return(ERROR);
            } else Pop(s,&e1);
            if (!Comp(e1,e[i])) {
                printf("ERROR
");
                //printf("%*s↖左右匹配出错
",i+1,"");
                return(ERROR);
            }
        }
    }
    if (!StackEmpty(s)) {
        //printf("%*s↖左括号多余
",i,"");
        printf("ERROR
");
        return(ERROR);
    } else {
        printf("OK
");
        return(OK);
    }
}
int main() {
    SpStack s;
    Count(&s);
    free(s.base);
    return 0;
}

4、两个已排序的数组进行合并

#include <iostream>
#include <assert.h>
#include<stdio.h>
#include<stdlib.h>
/*
*Describe:print the elements of the array
*Data:5/11/2013
*Author:pjgan
*Version:1
*tool:vc++2008
*/
void Global_printElements(const int *pArray,int Array_Length);

/*
*Return: true is sorted
*
*/
bool Global_isSort(const int  *pArray, int iArrayLeng);

/*
*Return: is the returlts of the Merge Array_A and Array_B
*/
void *Global_Merge(const int *Array_A, int Array_A_Length, const int *Array_B, int Array_B_Length);

void Global_printElements(const int *pArray,int Array_Length){
    assert(pArray);
    int i = 0;
    for( ; i < Array_Length; ++i) {
        std::cout<<pArray[i]<<" ";
    }
    std::cout<<std::endl;
}

bool Global_isSort(const int  *pArray, int iArrayLeng){
    assert(pArray);
    int i = 0;
    int j = 0;
    for( ; i < (iArrayLeng-1); ++i) {
        for( j = ( i + 1); j < iArrayLeng; ++j) {
            if(pArray[i] > pArray[j]) return false;
        }
    }
    return true;
}

void *Global_Merge(const int *Array_A, int Array_A_Length, const int *Array_B, int Array_B_Length) {
    assert(Array_A && Array_B);
    bool bArrayAisSorted = Global_isSort(Array_A, Array_A_Length);
    bool bArrayBisSorted = Global_isSort(Array_B, Array_B_Length);
    if(bArrayAisSorted && bArrayBisSorted) {
        /*
        * i,j are the index of the Array_A and the Array_B
        */
        int i = 0;
        int j = 0;

        int *pStoreMergeArrayData = new int[Array_A_Length + Array_B_Length];
        int  MergeArrayIndex = 0;
        while(i < Array_A_Length && j < Array_B_Length) {
            if(Array_A[i] < Array_B[j]) {
                pStoreMergeArrayData[MergeArrayIndex++] = Array_A[i++];
            } else {
                pStoreMergeArrayData[MergeArrayIndex++] = Array_B[j++];
            }
        }

        while(i < Array_A_Length) {
            pStoreMergeArrayData[MergeArrayIndex++] = Array_A[i++];
        }

        while(j < Array_B_Length) {
            pStoreMergeArrayData[MergeArrayIndex++] = Array_B[j++];
        }
        return pStoreMergeArrayData;
    } else {
        std::cout<<"merge failed"<<std::endl;
        //exit(1);
    }
    return NULL;
}

int main() {
    int a[] = {1, 2, 3, 5, 8};
    //int a[1005],b[1005],n,m,i1,j1;
    //scanf("%d %d",&n,&m);
    //for(i1=0;i1<n;i1++)
       // scanf("%d",&a[i1]);
    //for(j1=0;j1<m;j1++)
       // scanf("%d",&b[j1]);
    int b[] = {2, 6, 7, 10, 25, 33, 50};
    int *MergeArray = (int *)Global_Merge(a, 5, b, 6);
    Global_printElements(MergeArray, 5+6);
    if(MergeArray != NULL) {
        delete MergeArray;
        MergeArray = NULL;
    }
    return 0;
}

5、将一维数组中的元素向右循环移动k次

输入数据有多组，每组数据由两行组成，第一行是k和n，第二行n个整数的数列，数列中的元素以空格隔开。

#include <iostream>
#include<stdio.h>
#include<stdlib.h>
#include<malloc.h>

using namespace std;

void fun(int *a,int k,int n)
{ int i,j,m;
  for ( i=0;i<k;i++ ) { m=a[n-1]; for ( j=n-1;j>0;j-- ) a[j]=a[j-1]; a[0]=m; }
}

int main()
{ int k,n,i;
  int *a;
  while ( 1 )
  { scanf("%d",&n);
    if (n>=0)
      if ( a=(int *)malloc(n*sizeof(int)) )
      {    for ( i=0;i<n;i++ ) scanf("%d",a+i);
            scanf("%d",&k);
        fun(a,k,n);
        for ( i=0;i<n;i++ ) printf("%d ",a[i]); printf("
");
        free(a);
      }
  }
}

6、相邻最大差值

题目描述

请设计一个复杂度为O(n)的算法，计算一个未排序数组中排序后相邻元素的最大差值。 
给定一个整数数组A和数组的大小n，请返回最大差值。

#include <iostream>
#include <vector>
using namespace std;
class Gap {
public:
    int maxGap(vector<int> A, int n) {
        int var_max = A[0], var_min = A[0];
        for(int i = 1; i < n; i++){
            if(var_max < A[i])
                var_max = A[i];
            if(var_min > A[i])
                var_min = A[i];
        }
        if(var_max == var_min)
            return 0;

        double var_unit = (double)(var_max - var_min)/(double)n;
        // vector<int> bucket[n+1];
        vector<vector<int> > bucket(n+1);
        for(int i = 0; i < n; i++){
            bucket[getIndex(var_unit, A[i], var_min)].push_back(A[i]);
        }
        int res = -1, tmp;
        int index1 = 0, index2 = 1;
        while(index2 < n+1){
            // cout<<"index1: "<<index1<<"|| index2: "<<index2<<endl;
            if(!bucket[index1].empty() && !bucket[index2].empty()){
                tmp = getMin(bucket[index2]) - getMax(bucket[index1]);
                index1++, index2++;
                if(tmp > res)
                    res = tmp;
            }

            if(bucket[index1].empty())
                index1++;
            if(bucket[index2].empty())
                index2++;
        }
        return res;
    }
    int getIndex(double var_unit, int var, int var_min){
        return ((double)(var-var_min)/var_unit);
    }
    int getMax(vector<int> A){
        int tmp = A[0];
        for(int i = 1; i < A.size(); i++){
            if(tmp < A[i])
                tmp = A[i];
        }
        return tmp;
    }
    int getMin(vector<int> A){
        int tmp = A[0];
        for(int i = 1; i < A.size(); i++){
            if(tmp > A[i])
                tmp = A[i];
        }
        return tmp;
    }
};
int main()
{

    vector<int> A;
    //3429,6401,8559,1052,4775,6220,3593,2406,4995
    A.push_back(3429), A.push_back(6401), A.push_back(8559), A.push_back(1052), A.push_back(4775);
    A.push_back(6220), A.push_back(3593), A.push_back(2406), A.push_back(4995);
    Gap sorter;
    int res = sorter.maxGap(A, 9);

    cout<<res<<endl;

    return 0;
}