Item.h (自定义类型) :
1 typedef double Item;
STACK.h (下推栈接口) :
1 #include "Item.h"
2
3 bool STACKerror(int i);
4 void STACKinit(int);
5 int STACKempty(void);
6 void STACKpush(Item);
7 Item STACKpop(void);
STACK.c (接口源代码_数组实现) :
1 #include "STACK.h"
2 #include <stdlib.h>
3
4 static Item *s;
5 static int N,N1;
6
7 bool STACKerror(int i)
8 {
9 if(i)
10 return N<N1?true:false;
11
12 else
13 return N>0 ?true:false;
14 }
15 void STACKinit(int maxN)
16 {
17 s=malloc(maxN*sizeof(Item));
18 N=0;
19 N1=maxN;
20 }
21 int STACKempty(void)
22 {
23 return N;
24 }
25 void STACKpush(Item item)
26 {
27 if(STACKerror(1))
28 s[N++]=item;
29 else
30 printf("
STACKpush false");
31 }
32 Item STACKpop(void)
33 {
34 if(STACKerror(0))
35 return s[--N];
36 else
37 printf("
STACKpop false");
38 return -1;
39 }
STACK.c (接口源代码_链表实现) :
1 #include "STACK.h"
2 #include <stdlib.h>
3
4 typedef struct STACKnode *link;
5 struct STACKnode
6 {
7 Item item;
8 link next;
9 };
10
11 static link head;
12 static int N=0,N1;
13
14 bool STACKerror(int i)
15 {
16 if(i)
17 return N<N1?true:false;
18
19 else
20 return N>0 ?true:false;
21 }
22 link NEW(Item item, link next)
23 {
24 link x = malloc(sizeof *x);
25 x->item=item; x->next=next;
26 return x;
27 }
28 void STACKinit(int maxN)
29 {
30 N1=maxN;
31 head=NULL;
32 }
33 int STACKempty(void)
34 {
35 return N;
36 }
37 void STACKpush(Item item)
38 {
39 if(STACKerror(1))
40 {
41 head=NEW(item, head);
42 N++;
43 }
44 else
45 printf("
STACKpush false");
46 }
47 Item STACKpop(void)
48 {
49 if(STACKerror(0))
50 {
51 Item item=head->item;
52 link t=head->next;
53 free(head);head=t;
54 N--;
55 return item;
56 }
57 else
58 printf("
STACKpop false");
59 return -1;
60 }
STACK.c (接口源代码_双向链表实现) :
1 #include<stdlib.h>
2 #include "STACK.h"
3
4 typedef struct node * link;
5 struct node
6 {
7 Item item;
8 link next,last;
9 };
10
11 static link head,last;
12 static int N=0,N1=0;
13
14 link NEW(Item item, link last)
15 {
16 link x=malloc(sizeof (link));
17 x->item=item;
18 //x->next=head;
19 x->next=NULL;
20 x->last=last;
21 return x;
22 }
23 static short STACKerror(short i)
24 {
25 if(i)
26 {
27 if(N<N1)
28 return 1;
29 printf("
STACKpush false !
");
30 exit(1);
31 }
32 else
33 {
34 if(N>0)
35 return 1;
36 printf("
STACKpop false !
");
37 exit(1);
38 }
39 }
40 void STACKinit(int maxN)
41 {
42 last=head=NULL;
43 N1=maxN;
44 }
45 void STACKpush(Item item)
46 {
47 if(STACKerror(1))
48 {
49 head=NEW(item, last);
50 last=head;
51 N++;
52 }
53 }
54 Item STACKpop(void)
55 {
56 if(STACKerror(0))
57 {
58 Item i=head->item;
59 link x=head;
60 head=head->last;
61 last=head;
62 free(x);
63 N--;
64 return i;
65 }
66 }
67 int STACKempty(void)
68 {
69 return N;
70 }
main.c (主程序_打印中缀-后缀表达式) :
1 #include <stdio.h>
2 #include <string.h>
3 #include "STACK.h"
4
5 int main(void)
6 {
7 char a[20];
8 double temp;
9
10 scanf("%s",a);
11 getchar();
12
13 int N=strlen(a);
14 STACKinit(N);
15
16 for(int i=0; i<N; i++)
17 {
18 if(a[i]==')')
19 {
20 printf("%c ", (int)STACKpop());
21 }
22 else if((a[i]=='+')||(a[i]=='*')||(a[i]=='-')||(a[i]=='/'))
23 {
24 STACKpush(a[i]);
25 }
26 else if((a[i]>='0')&&(a[i]<='9'))
27 {
28 printf("%c ",a[i]);
29 }
30 }
31 putchar('
');
32
33 return 0;
34 }
测试结果：
main.c (主程序_后缀表达式求值) :
1 #include <stdio.h>
2 #include <string.h>
3 #include "STACK.h"
4
5 int main(void)
6 {
7 char a[20];
8 double temp;
9
10 scanf("%s",a);
11 getchar();
12
13 int N=strlen(a);
14 STACKinit(N);
15 for(int i=0; i<N; i++)
16 {
17 if((a[i]>='0')&&(a[i]<='9'))
18 STACKpush(a[i]-'0');
19 else if(a[i]=='+')
20 {
21 //STACKpush(STACKpop()+STACKpop());
22 temp=STACKpop();
23 STACKpush(STACKpop()+temp);
24 }
25 else if(a[i]=='*')
26 {
27 //STACKpush(STACKpop()*STACKpop());
28 temp=STACKpop();
29 STACKpush(STACKpop()*temp);
30 }
31 else if(a[i]=='/')
32 {
33 temp=STACKpop();
34 STACKpush(STACKpop()/temp);
35 }
36 else if(a[i]=='-')
37 {
38 temp=STACKpop();
39 STACKpush(STACKpop()-temp);
40 }
41 //while((a[i]>='0')&&(a[i]<='9'))
42 //STACKpush(10*STACKpop()+(a[i++]-'0'));
43 }
44 printf("%f
", STACKpop());
45 return 0;
46 }
测试结果：
