C数据结构：栈和队列应用场景

计算器实例

main.c

#include <stdlib.h>
#include <stdio.h>
#include "sqstack.h"void compute(sqstack* snum,datatype* data)
{datatype n1,n2,n;st_pop(snum,&n2);st_pop(snum,&n1);switch(*data){case '+':n = n1 +n2;break;case '-':n = n1 - n2;break;case '*':n = n1 * n2;break;case '/':n = n1 / n2;break;default:exit(1);break;}st_push(snum,&n);}
int get_pri(int op)
{switch(op){case '(':return 0;case '+':return 1;case '-':return 1;case '*':case '/':return 2;}
}
void deal_bracket(sqstack*snum ,sqstack* sop)
{datatype old_op;st_top(sop,&old_op);while(old_op != '('){st_pop(sop,&old_op);compute(snum,&old_op);st_top(sop,&old_op);}st_pop(sop,&old_op); //弹出左括号}
void deal_op(sqstack*snum,sqstack*sop,int op)
{datatype old_op;if( (st_isempty(sop)==0) ||op =='('  )  {st_push(sop,&op);return ;}st_top(sop,&old_op);if(get_pri(op) > get_pri(old_op)){st_push(sop,&op);return;}while( get_pri(op) <= get_pri(old_op) ){st_pop(sop,&old_op);compute(snum,&old_op);if(st_isempty(sop)== 0)break;st_top(sop,&old_op);}st_push(sop,&op);}
int main()
{datatype old_op;int i=0;int value =0;int flag = 0;char str[] = "(11+3)*2-5"; //23sqstack*snum,*sop;snum = st_create();sop = st_create();while(str[i] != '\0'){// printf("%c  \n",str[i]);// numif(str[i]> '0' && str[i]< '9' ){value = value*10 + (str[i]- '0') ;  //求差值,原来内容移位flag = 1;}else // op{if(flag == 1) //证明取过了数值{st_push(snum,&value);value = 0;flag = 0;}if(str[i]==')'){deal_bracket(snum,sop);}else // 可能是  ( + - * / {deal_op(snum,sop,str[i]);}}i++;}if(flag) //最后一个元素{st_push(snum,&value);}st_travel(snum);printf("--------\n"); while(!(st_isempty(sop)==0) ){st_pop(sop,&old_op);compute(snum,&old_op);if(st_isempty(sop)==0)break;st_top(sop,&old_op);}st_travel(snum);st_destroy(snum);st_destroy(sop);return 0;
}

sqstack.h

#ifndef SQSTACK_H
#define SQSTACK_H#define MAXSIZE 32typedef int datatype;typedef struct node_st
{datatype data[MAXSIZE];int top;
}sqstack;sqstack* st_create(void);int st_isempty(sqstack*);int st_push(sqstack*,datatype*);int st_pop(sqstack*,datatype*);int st_top(sqstack*,datatype*);void st_travel(sqstack*);int st_destroy(sqstack*);#endif

sqstack.c

#include <stdlib.h>
#include <stdio.h>
#include "sqstack.h"sqstack* st_create(void)
{sqstack*st;st = malloc(sizeof(*st));if(st == NULL)return NULL;st->top = -1;return st;
}
int st_isempty(sqstack*st)
{if(st->top == -1)return 0;return 1;
//    return (st->top == -1);
}
int st_push(sqstack*st,datatype* data)
{if(st->top == MAXSIZE-1 )return -1;st->data[++st->top] = *data;return 0;
}
int st_pop(sqstack*st,datatype*data)
{if(st_isempty(st)==0)return -1;*data = st->data[st->top--];return 0;
}
int st_top(sqstack*st,datatype*data)
{if(st_isempty(st )== 0)return -1;*data = st->data[st->top];return 0;
}
void st_travel(sqstack*st)
{if(st_isempty(st)== 0)return;for(int i=0;i<=st->top;i++){printf("%d ",st->data[i]);}printf("\n");
}int st_destroy(sqstack*st)
{free(st);st = NULL;return 0;
}

球钟算法

代码中包含的sqstack.h/sqstack.c和 queue.h/queue.c参考之前文章：C数据结构栈，C数据结构队列，采用的是顺序存储栈，顺序存储队列，如有疑问，可以给博主留言。

main.c

#include <stdlib.h>
#include <stdio.h>
#include "sqstack.h"
#include "queue.h"#define BALL_SIZE 27
static int check(queue*qu)
{int i = (qu->head+1)%MAXSIZE;while(i != qu->tail ){if(qu->data[i] > qu->data[(i+1)%MAXSIZE ])return 0;i = (i+1)%MAXSIZE;}return 1;
}int main()
{int t,time = 0;queue* qu;int value = 0;sqstack*st_min,*st_fivemin,*st_hour;qu = qu_create();st_min = st_create();st_fivemin = st_create();st_hour = st_create();for(int i=1;i<=BALL_SIZE;i++){qu_enqueue(qu,&i);}qu_travel(qu);while(1){qu_dequeue(qu,&t);time++;if(st_min->top != 3){st_push(st_min,&t);}else{while(st_isempty(st_min)!=0){st_pop(st_min,&value);qu_enqueue(qu,&value);}if(st_fivemin->top !=10){st_push(st_fivemin,&t);}else{while(st_isempty(st_fivemin)!=0 ){st_pop(st_fivemin,&value);qu_enqueue(qu,&value);}if(st_hour->top != 10){st_push(st_hour,&t);}else{while(st_isempty(st_hour) !=0 ){st_pop(st_hour,&value);qu_enqueue(qu,&value);}qu_enqueue(qu,&t);if(check(qu))break;}}}}printf("time = %d \n",time);qu_destroy(qu);st_destroy(st_min);st_destroy(st_fivemin);st_destroy(st_hour);return 0;
}