栈与队列应用：二进制转十进制 八进制 十六进制（栈）

//将二进制转化为十进制（利用后入先出的特点）
//二进制数 1101001 
/*   top  
   1 
   0
   0
   1
   0
   0
   1
   1 base */ 
 
#include<stdio.h>
#include<stdlib.h>
#include<math.h>

#define STACK_INIT_SIZE 20
#define STACKINCREMENT 10

typedef char ElemType; //如果用int则相当于给计算机一个整形

typedef struct
{
    ElemType *base;
    ElemType *top;
    int stackSize;
}sqStack;

void InitStack(sqStack *s)
{
    s->base = (ElemType *)malloc(STACK_INIT_SIZE*sizeof(ElemType));
    if(!s->base)
    {
        exit(0);
    }
    s->top = s->base; //初始化栈顶等于栈底 
    s->stackSize = STACK_INIT_SIZE; 
}

void Push(sqStack *s,ElemType e)
{
    if(s->top - s->base >= s->stackSize)//检查栈是否已经满了 如果满了再申请空间 
    {
        s->base = (ElemType *)realloc(s->base,(s->stackSize+STACKINCREMENT)*sizeof(ElemType));
        if(!s->base)
        {
            exit(0);
        }
    }  
    *(s->top) = e;
    s->top++;
}

void Pop(sqStack *s,ElemType *e)//弹 
{
    if(s->top == s->base)
    {
        return;
    }
    *e = *--(s->top); 
}

int StackLen(sqStack s)//测量长度不需要对栈进行修改 所以不需要使用指针 
{//传进来的是一个结构 
    return (s.top - s.base);
}

int main(void)
{
    ElemType c;
    sqStack s;
    
    int len,i,sum = 0;
    
    InitStack(&s);//初始化 
    
    printf("请输入二进制数，输入#符号表示结束！\n");
    scanf("%c",&c);
    
    while(c != '#')
    {
        Push(&s,c);
        scanf("%c",&c);
    }
    
    getchar(); //过滤回撤
    len = StackLen(s); 
    printf("栈的当前容量是：%d\n",len);
    
    for(i = 0; i < len; i++)
    {
        Pop(&s,&c);
        sum = sum + (c-48)*pow(2,i);
    }
    
    printf("转化为十进制数是:%d\n",sum); 
    return 0;
}

//二进制转化为八进制
例如（15）10 = （1111）2 = （17）8
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define SIZE 20
#define STACKINCREMENT 10
typedef char ElemType;//如果定义int，一串数字都会一起放入
typedef struct
{
    ElemType *base;
    ElemType *top;
    int stackSize;
}sqStack;
void InitStack(sqStack *s)
{
    s->base=(ElemType *)malloc(SIZE*sizeof(ElemType));
    if(!s->base)
        exit(0);
    s->top=s->base;
    s->stackSize=SIZE;
}
void Push(sqStack *s,ElemType e)
{
    if(s->top-s->base==s->stackSize)
    {
        s->base=(ElemType *)realloc(s->base,(s->stackSize+STACKINCREMENT)*sizeof(ElemType));
        if(!s->base)
            exit(0);
        s->top=s->base+s->stackSize;
        s->stackSize=s->stackSize+STACKINCREMENT;
    }
    *(s->top)=e;
    s->top++;
}
int Pop(sqStack *s,ElemType *e)
{
    if(s->top==s->base)
        return 0;
    *e=*(--(s->top));
    return 1;

}
int StackLen(sqStack s)//测试传数据，修改传指针
{
    return(s.top-s.base);
}
int main()
{
    ElemType c,ch,chi;
    sqStack s,q;
    int len1,len2,i,j,k,sum=0;
    InitStack(&s);
    InitStack(&q);
    printf("请输入二进制数：输入#符号表示结束\n");
    scanf("%c",&c);
    while(c!='#')
    {
        Push(&s,c);
        scanf("%c",&c);
    }
    getchar();//吸收回车
    len1=StackLen(s);
    for(i=0;i<len1;i=i+3)
    {
        for(j=0;j<3;j++)
        {
            Pop(&s,&c);
            sum+=(c-48)*pow(2,j);
            if( s.base == s.top )
                break;
        }
        chi=sum+'0';
        Push(&q,chi);
        sum=0;//每次循环结束，sum要清零
    }
    len2=StackLen(q);
    printf("转换后八进制数是:");
    for(k=0;k<len2;k++)
    {
        Pop(&q,&ch);
        printf("%c",ch);
    }
    return 0;
}



//二进制转化为十六进制
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define SIZE 20
#define STACKINCREMENT 10
typedef char ElemType;
typedef struct
{
    ElemType *base;
    ElemType *top;
    int stackSize;
}sqStack;
void InitStack(sqStack *s)
{
    s->base=(ElemType *)malloc(SIZE*sizeof(ElemType));
    if(!s->base)
        exit(0);
    s->top=s->base;
    s->stackSize=SIZE;
}
void Push(sqStack *s,ElemType e)
{
    if(s->top-s->base==s->stackSize)
    {
        s->base=(ElemType *)realloc(s->base,(s->stackSize+STACKINCREMENT)*sizeof(ElemType));
        if(!s->base)
            exit(0);
        s->top=s->base+s->stackSize;
        s->stackSize=s->stackSize+STACKINCREMENT;
    }
    *(s->top)=e;
    s->top++;
}
int Pop(sqStack *s,ElemType *e)
{
    if(s->top==s->base)
        return 0;
    *e=*(--(s->top));
    return 1;

}
int StackLen(sqStack s)//测试传数据，修改传指针
{
    return(s.top-s.base);
}
int main()
{
    ElemType c,ch,chi;
    sqStack s,q;
    int len1,len2,i,j,k,sum=0;
    InitStack(&s);
    InitStack(&q);
    printf("请输入二进制数：输入#符号表示结束\n");
    scanf("%c",&c);
    while(c!='#')
    {
        Push(&s,c);
        scanf("%c",&c);
    }
    getchar();//吸收回车
    len1=StackLen(s);
    for(i=0;i<len1;i=i+4)
    {
        for(j=0;j<4;j++)
        {
            Pop(&s,&c);
            sum+=(c-48)*pow(2,j);
            if( s.base == s.top )
                break;
        }
        chi=sum+'0';
        switch(sum)
        {
            case 10:
                chi='A';
                break;
            case 11:
                chi='B';
                break;
            case 12:
                chi='C';
                break;
            case 13:
                chi='D';
                break;
            case 14:
                chi='E';
                break;
            case 15:
                chi='F';
                break;
        }
        Push(&q,chi);
        sum=0;//每次循环结束，sum要清零
    }
    len2=StackLen(q);
    printf("转换后十六进制数是:");
    for(k=0;k<len2;k++)
    {
        Pop(&q,&ch);
        printf("%c",ch);
    }
    return 0;
}