1 #include <stdlib.h> 2 #include <malloc.h> 3 #include <stdio.h> 4 5 typedef struct Node 6 { 7 int data; 8 struct Node *pNext; 9 }NODE,*PNODE; 10 11 PNODE create_list(void); 12 void traverse_list(PNODE); 13 bool is_empty(PNODE pHead); 14 int length_list(PNODE); 15 bool insert_list(PNODE, int, int); 16 bool delete_list(PNODE,int,int*); 17 void sort_list(PNODE); 18 19 int main(void) 20 { 21 PNODE pHead = NULL; 22 int val; 23 pHead = create_list(); 24 sort_list(pHead); 25 if (delete_list(pHead, 4, &val)) 26 { 27 printf("delete %d ok!\n",val); 28 } 29 else 30 { 31 printf("delete wrong"); 32 } 33 traverse_list(pHead); 34 int len = length_list(pHead); 35 if (is_empty(pHead)) 36 { 37 printf("list is empty!"); 38 } 39 else 40 { 41 printf("list isn't empty!"); 42 } 43 return 0; 44 } 45 46 PNODE create_list(void) 47 { 48 int len; 49 int val;//用于存放用户输入的结点的值 50 printf("请输入链表的长度:len="); 51 scanf("%d", &len); 52 PNODE pHead = (PNODE)malloc(sizeof(Node)); 53 54 if (NULL == pHead) 55 { 56 printf("分配失败,程序终止!"); 57 exit(-1); 58 } 59 PNODE pTail = pHead; 60 pTail->pNext = NULL; 61 62 for (int i = 0; i < len; ++i) 63 { 64 printf("请输入第%d个节点的值", i + 1); 65 scanf("%d", &val); 66 PNODE pNew = (PNODE)malloc(sizeof(Node)); 67 if (NULL == pNew) 68 { 69 printf("分配失败,程序终止!"); 70 exit(-1); 71 } 72 pNew->data = val; 73 pTail->pNext = pNew; 74 pNew->pNext = NULL; 75 pTail = pNew; 76 } 77 return pHead; 78 } 79 80 void traverse_list(PNODE pHead) 81 { 82 PNODE p = pHead->pNext; 83 while (NULL != p) 84 { 85 printf("%d", p->data); 86 p = p->pNext; 87 } 88 printf("\n"); 89 } 90 91 bool is_empty(PNODE pHead) 92 { 93 if (NULL == pHead->pNext) 94 { 95 return true; 96 } 97 return false; 98 } 99 100 int length_list(PNODE pHead) 101 { 102 int length = 0; 103 PNODE p = pHead->pNext; 104 while (NULL != p) 105 { 106 length++; 107 p = p->pNext; 108 } 109 return length; 110 } 111 112 void sort_list(PNODE pHead) 113 { 114 int i, j, t; 115 int len = length_list(pHead); 116 PNODE p, q; 117 for (i = 0, p = pHead->pNext; i < len - 1; ++i, p=p->pNext) 118 { 119 for (j = i + 1, q = p->pNext; j < len; ++j, q = q->pNext) 120 { 121 if (p->data > q->data) 122 { 123 t = p->data; 124 p->data = q->data; 125 q->data = t; 126 } 127 } 128 } 129 return; 130 } 131 //在pHead指向链表的第pos个节点的前面插入一个新的节点,该节点的值为value,pos从1开始 132 bool insert_list(PNODE pHead, int pos, int value) 133 { 134 int i = 0; 135 PNODE p = pHead; 136 while (NULL != p && i < pos - 1) 137 { 138 p = p->pNext; 139 ++i; 140 } 141 if (i > pos - 1 || NULL == p) 142 return false; 143 PNODE pNew = (PNODE)malloc(sizeof(NODE)); 144 if (NULL == pNew) 145 { 146 printf("动态分配内存失败!\n"); 147 exit(-1); 148 } 149 pNew->data = value; 150 PNODE q = p->pNext; 151 p->pNext = pNew; 152 pNew->pNext = q; 153 return true; 154 } 155 156 bool delete_list(PNODE pHead, int pos, int *pVal) 157 { 158 int i = 0; 159 PNODE p = pHead; 160 while (NULL != p->pNext && i < pos - 1) 161 { 162 p = p->pNext; 163 ++i; 164 } 165 if (i > pos - 1 || NULL == p->pNext) 166 { 167 return false; 168 } 169 PNODE q = p->pNext; 170 *pVal = q->data; 171 //删除p节点后面的节点 172 p->pNext = p->pNext->pNext; 173 free(q); 174 q = NULL; 175 return true; 176 } 177 178 179 /* 180 1.链表的删除,比如删除p后的节点,如何操作?有时很容易遗漏free(r)的操作,导致内存泄漏。 181 可以如下操作: 182 r = p->next; 183 p->next = r->next; 184 free(r); 185 */
怕什么真理无穷,进一寸有一寸的欢喜。---胡适