justhomework/ex2/ex2.cpp

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

class Vec
{
private:
  int *v;
  int LEN;
  int USED;

  void expand();

  void shrink();

public:
  Vec(int len);

  int get(int a);

  void put(int a, int value);

  void swap(int a, int b);

  int insert(int locate, int value);

  int del(int locate, int value);

  int find(int value);

  void printall();

  int getlen();

  int getused();
};

Vec::Vec(int len)
{
  LEN = len * 2;
  v = new int[LEN];
  USED = 9;

  for (int i = 0; i < 10; i++)
    v[i] = i + 1;

  for (int i = 0; i < 10; i++)
    swap(i, rand() % 10);
}

int Vec::get(int a)
{
  return v[a];
}

void Vec::put(int a, int value)
{
  v[a] = value;
}

void Vec::swap(int a, int b)
{
  int temp = v[a];
  v[a] = v[b];
  v[b] = temp;
}

void Vec::expand()
{
  LEN = LEN * 2;
  int *p = new int[LEN];

  for (int i = 0; i <= USED; i++)
    p[i] = v[i];

  delete[] v;
  v = p;
}

void Vec::shrink()
{
  LEN = LEN >> 1;
  int *p = new int[LEN];

  for (int i = 0; i <= USED; i++)
    p[i] = v[i];

  delete[] v;
  v = p;
}

int Vec::insert(int locate, int value)
{
  if (locate < 0 || locate > USED)
    return 1;

  USED++;

  if (USED >= LEN)
    expand();

  for (int i = USED; i > locate; i--)
    v[i] = v[i - 1];

  v[locate] = value;

  return 0;
}

int Vec::del(int locate, int value)
{

  if (locate < 0 || ((USED - value) < 0) || ((locate + value - 1) > USED))
    return 1;

  USED = USED - value;

  for (int i = locate; i <= USED; i++)
    v[i] = v[i + value];

  if (((double)USED / (double)LEN) <= 0.3)
    shrink();

  return 0;
}

int Vec::find(int value)
{
  int i = 0;
  for (i; i <= USED; i++)
  {
    if (v[i] == value)
    {
      return i;
    }
  }

  return -1;
}

int Vec::getlen()
{
  return LEN;
}

int Vec::getused()
{
  return USED;
}

void Vec::printall()
{
  for (int i = 0; i < USED; i++)
    printf("%d\n", v[i]);
}

int main()
{
  srand(time(NULL));

  Vec v(10);
  int temp[10] = {0};
  int flag;

  printf("初始化，输出数组\n");
  v.printall();

  while (1)
  {
    printf("选择操作:1.插入 2.删除 3.查找\n");
    scanf("%d", &flag);

    switch (flag)
    {
    case 1:
      printf("输入秩与待插入数值\n");
      scanf("%d %d", &temp[0], &temp[1]);
      (v.insert(temp[0], temp[1])) ? (printf("非法输入\n")) : (printf("输出数组\n"));
      v.printall();
      break;

    case 2:
      printf("输入秩与待删除个数\n");
      scanf("%d %d", &temp[0], &temp[1]);
      (v.del(temp[0], temp[1])) ? (printf("非法输入\n")) : (printf("输出数组\n"));
      v.printall();
      break;

    case 3:
      printf("输入要查找的数值\n");
      scanf("%d", &temp[0]);
      temp[2] = v.find(temp[0]);

      (temp[2] == -1) ? (printf("无此元素\n")) : (printf("秩为%d \n", temp[2]));
      break;

    default:
      printf("返回菜单\n");
    }

    flag = 0;
  }
  return 0;
}