順序表 1.順序表定義:線性表的順序表示指的是用一組地址連續的存儲單元依次存儲線性表的數據元素。假設線性表的每個元素需占用L個 存儲單元,並以所占的第一個單元的存儲地址作為數據元素的存儲位置。則線性表中第i+1個數據元素的存儲位置LOC(ai+1)和第i個數據 元素的存儲位置LOC(ai)之間滿足下 ...
順序表
1.順序表定義:線性表的順序表示指的是用一組地址連續的存儲單元依次存儲線性表的數據元素。假設線性表的每個元素需占用L個
存儲單元,並以所占的第一個單元的存儲地址作為數據元素的存儲位置。則線性表中第i+1個數據元素的存儲位置LOC(ai+1)和第i個數據
元素的存儲位置LOC(ai)之間滿足下列關係:LOC(ai+1)=LOC(ai)+L,一般來說,線性表的第i個數據元素ai的存儲位置為:LOC(ai)=LOC(a1)
+(i-1)*L,式中LOC(ai)是線性表的第一個數據元素a1的存儲位置,通常稱作線性表的起始位置或基地址。
2.順序表的數據結構
typedef struct SeqList { ElemType *base; size_t capacity; size_t len; }SeqList;
3. 在順序表中有以下操作:
void InitSeqList(SeqList *list); void ShowSeqList(SeqList *list); bool push_back(SeqList *list, ElemType x); bool push_front(SeqList *list, ElemType x); size_t Length(SeqList *list); bool insert_pos(SeqList *list, int pos, ElemType x); bool pop_back(SeqList *list); bool pop_front(SeqList *list); bool insert_val(SeqList *list, ElemType x); bool delete_pos(SeqList *list, int pos); bool delete_val(SeqList *list, ElemType key); int find_key(SeqList *list, ElemType key); void reverse_list(SeqList *list); void sort_list(SeqList *list); void clear_list(SeqList *list); void destroy_list(SeqList *list);
以上操作包括(1)初始化一個順序表來構造一個空的順序表.(2)展示順序表.(3)尾插法.(3)頭插法.(4)求順序表的長度.
(5)按位置將一個數據元素插入順序表中.(6)尾部刪除元素.(7)頭部刪除元素.(8)按值的大小插入順序表中.(9)按位置刪
除順序表中的元素.(10)按值刪除順序表中的元素.(11)按值查找順序表中的元素.(12)將順序表逆置.(13)將順序表的元素
進行排序.(14)清除順序表.(15)銷毀順序表.
4.下麵將上面所聲明的方法在SeqList.h的頭文件中進行實現如下:
#ifndef _SEQLIST_H #define _SEQLIST_H
#include<iostream>
#include<assert.h>
using namespace std;
#define ElemType int
#define SEQLIST_DEFAULT_SIZE 8
#define SEQLIST_INC_SIZE 3
typedef struct SeqList { ElemType *base; size_t capacity; size_t len; }SeqList;
void InitSeqList(SeqList *list); void ShowSeqList(SeqList *list); bool push_back(SeqList *list, ElemType x); bool push_front(SeqList *list, ElemType x); size_t Length(SeqList *list); bool insert_pos(SeqList *list, int pos, ElemType x); bool pop_back(SeqList *list); bool pop_front(SeqList *list); bool insert_val(SeqList *list, ElemType x); bool delete_pos(SeqList *list, int pos); bool delete_val(SeqList *list, ElemType key); int find_key(SeqList *list, ElemType key); void reverse_list(SeqList *list); void sort_list(SeqList *list); void clear_list(SeqList *list); void destroy_list(SeqList *list); bool IsFull(SeqList *list) { return list->len >= list->capacity; } bool IsEmpty(SeqList *list) { return list->len == 0; } void Swap(ElemType &a, ElemType &b) { ElemType tmp = a; a = b; b = tmp; }
//異常安全 bool Inc(SeqList *list) { size_t new_capacity = list->capacity+SEQLIST_INC_SIZE; ElemType *new_base = (ElemType*)realloc(list->base, sizeof(ElemType)*new_capacity); if(new_base == NULL) return false; list->capacity = new_capacity; list->base = new_base; return true; }
void InitSeqList(SeqList *list) { list->base = (ElemType*)malloc(sizeof(ElemType)*SEQLIST_DEFAULT_SIZE); assert(list->base != NULL); list->capacity = SEQLIST_DEFAULT_SIZE; list->len = 0; }
void ShowSeqList(SeqList *list) { for(int i=0; i<list->len; ++i) { cout<<list->base[i]<<" "; } cout<<endl; } bool push_back(SeqList *list, ElemType x) { if(list->len>=list->capacity && !Inc(list)) //if(!Inc(list) && list->len>=list->capacity) { cout<<"空間已滿,"<<x<<"不能尾部插入."<<endl; return false; } list->base[list->len++] = x; //list->len++; return true; } bool push_front(SeqList *list, ElemType x) { if(list->len >= list->capacity) { cout<<"空間已滿,"<<x<<"不能頭部插入."<<endl; return false; } for(int i=list->len; i>0; --i) { list->base[i] = list->base[i-1]; } list->base[0] = x; list->len++; return true; } size_t Length(SeqList *list) { return list->len; } bool insert_pos(SeqList *list, int pos, ElemType x) { if(list->len >= list->capacity) { cout<<"空間已滿,"<<x<<"不能插入."<<endl; return false; } if(pos<0 || pos>list->len) { cout<<"插入的位置非法."<<endl; return false; } for(int i=list->len; i>pos; --i) { list->base[i] = list->base[i-1]; } list->base[pos] = x; list->len++; return true; }
bool pop_back(SeqList *list) { if(list->len == 0) { cout<<"順序表已空,不能刪除."<<endl; return false; } list->len--; return true; } bool pop_front(SeqList *list) { if(list->len == 0) { cout<<"順序表已空,不能刪除."<<endl; return false; } for(int i=0; i<list->len-1; ++i) { list->base[i] = list->base[i+1]; } list->len--; return true; } bool insert_val(SeqList *list, ElemType x) { if(list->len >= list->capacity) { cout<<"空間已滿,"<<x<<"不能插入."<<endl; return false; } for(int i=0; i<list->len; ++i) { if(x < list->base[i]) { for(int j=list->len; j>i; --j) { list->base[j] = list->base[j-1]; } break; } } list->base[i] = x; list->len++; return true; } bool delete_pos(SeqList *list, int pos) { if(list->len == 0) { cout<<"順序表已空,不能刪除."<<endl; return false; } if(pos<0 || pos>=list->len) { cout<<"刪除的位置非法,不能刪除元素."<<endl; return false; } for(int i=pos; i<list->len-1; ++i) { list->base[i] = list->base[i+1]; } list->len--; return true; } bool delete_val(SeqList *list, ElemType key) { if(list->len == 0) { cout<<"順序表已空,不能刪除."<<endl; return false; } int del_pos = find_key(list, key); if(del_pos == -1) { cout<<"要刪除的數據:"<<key<<"不存在."<<endl; return false; } return delete_pos(list, del_pos); } int find_key(SeqList *list, ElemType key) { for(int i=0; i<list->len; ++i) { if(key == list->base[i]) return i; } return -1; } void reverse_list(SeqList *list) { if(list->len > 1) { int low = 0; int high = list->len-1; while(low < high) { Swap(list->base[low], list->base[high]); low++; high--; } } } void sort_list(SeqList *list) { if(list->len > 1) { for(int i=0; i<list->len-1; ++i) { for(int j=0; j<list->len-i-1; ++j) { if(list->base[j] > list->base[j+1]) { Swap(list->base[j], list->base[j+1]); } } } } } void clear_list(SeqList *list) { list->len = 0; } void destroy_list(SeqList *list) { free(list->base); list->base = NULL; // 預防野指針 list->capacity = list->len = 0; } #endif
5.將上面實現的方法在主函數中調用如下:
#include <iostream>
#incldue "SeqList.h"
using namespace std;
int main() { SeqList mylist; InitList(&mylist); ElemType item; int pos; int select = 1; while(select) { cout<<"******************************************"<<endl; cout<<"*[1] push_back [2] push_front *"<<endl; cout<<"*[3] show_list [0] quit_system *"<<endl; cout<<"*[4] pop_back [5] pop_front *"<<endl; cout<<"*[6] insert_pos [7] insert_val *"<<endl; cout<<"*[8] delete_pos [9] delete_val *"<<endl; cout<<"*[10] find_key [11] length *"<<endl; cout<<"*[12] reverse_list [13] sort *"<<endl; cout<<"*[14] clear_list *"<<endl; cout<<"******************************************"<<endl; cout<<"請選擇:>"; cin>>select; switch(select) { case 1: cout<<"請輸入要插入的數據(-1結束):>"; while(cin>>item, item!=-1) { push_back(&mylist, item); } break; case 2: cout<<"請輸入要插入的數據(-1結束):>"; while(cin>>item, item!=-1) { push_front(&mylist, item); } break; case 3: ShowList(&mylist); break; case 4: pop_back(&mylist); break; case 5: pop_front(&mylist); break; case 6: cout<<"請輸入要插入的位置:>"; cin>>pos; cout<<"請輸入要插入的值:>"; cin>>item; insert_pos(&mylist, pos, item); break; case 7: cout<<"請輸入要插入的值:>"; cin>>item; insert_val(&mylist, item); break; case 8: cout<<"請輸入要刪除的位置:>"; cin>>pos; delete_pos(&mylist, pos); break; case 9: cout<<"請輸入要刪除的值:>"; cin>>item; delete_val(&mylist, item); break; case 10: cout<<"請輸入要查找的值:>"; cin>>item; p = find_key(&mylist, item); if(p == NULL) { cout<<"要查找的值:"<<item<<"不存在!"<<endl; } break; case 11: cout<<"SeqList Length = "<<Length(&mylist)<<endl; break; case 12: reverse_list(&mylist); break; case 13: sort_list(&mylist); break; case 14: clear_list(&mylist); break; } system("pause"); system("cls"); } destroy_list(&mylist); return 0; }
在上述代碼的實現中bool Inc(SeqList *list);方法的實現過程是讓該順序表可以隨著數據的插入增長順序表的長度也隨之增長,然後
再進行頭插法或者尾插法的時候就不用擔心順序表的空間滿了不能插入的問題了。