栈 - 链表实现
代码如下：
1 #include <cstdio> 2 #include <cstdlib> 3 4 typedef int itemType; 5 struct Node; 6 typedef struct Node *pNode; 7 typedef pNode stack; 8 9 struct Node { 10 itemType item; 11 pNode next; 12 }; 13 14 int 15 IsEmpty(stack s) 16 { 17 return s->next == NULL; 18 } 19 20 void 21 Pop(stack s) 22 { 23 pNode tmp; 24 if (!IsEmpty(s)) { 25 tmp = s->next; 26 s->next = s->next->next; 27 free(tmp); 28 } 29 } 30 31 itemType 32 Top(stack s) 33 { 34 if (!IsEmpty(s)) { 35 return s->next->item; 36 } else { 37 printf("Stack is empty!\n"); 38 return -1; 39 } 40 } 41 42 void 43 Push(itemType x, stack s) 44 { 45 pNode tmp; 46 47 tmp = (pNode)malloc(sizeof(struct Node)); 48 if (tmp == NULL) { 49 printf("Out of space!\n"); 50 return; 51 } else { 52 tmp->item = x; 53 tmp->next = s->next; 54 s->next = tmp; 55 } 56 } 57 58 void 59 MakeEmpty(stack s) 60 { 61 if (s == NULL) { 62 printf("Must use CreateStack first!\n"); 63 return; 64 } else { 65 while (!IsEmpty(s)) { 66 Pop(s); 67 } 68 } 69 } 70 71 stack 72 CreateStack(void) 73 { 74 stack s; 75 76 s = (stack)malloc(sizeof(struct Node)); 77 if (s == NULL) { 78 printf("out of space!\n"); 79 return NULL; 80 } 81 s->next = NULL; 82 MakeEmpty(s); 83 return s; 84 } 85 86 void 87 DisposeStack(stack s) 88 { 89 pNode tmp, p; 90 91 while(!IsEmpty(s)) { 92 tmp = s->next; 93 s->next = tmp->next; 94 free(tmp); 95 } 96 free(s); 97 } 98 99 int 100 main(int argc, char** argv) 101 { 102 stack s; 103 104 s = CreateStack(); 105 Push(2, s); 106 Push(3, s); 107 Push(5, s); 108 Pop(s); 109 Pop(s); 110 Pop(s); 111 Pop(s); 112 printf("%d\n", Top(s)); 113 114 DisposeStack(s); 115 s = NULL; 116 117 system("pause"); 118 return(0); 119 }
