写了个算术表达式求值，有些缺陷，输入运算数时只能输入0~9。
#include <stdio.h>#include <stdlib.h>#define STACK_INIT_SIZE 100#define STACKINCREMENT 10#define OVERFLOW -2#define INFEASIBLE -1#define ERROR 0#define OK 1#define TRUE 1#define FALSE 0typedef struct //运算符栈
...{
char *base; char *top; int stacksize;
}SqStack;typedef struct //运算数栈...{ int *base; int *top; int stacksize;}sqStack;//一些栈的基本操作int InitStack(SqStack* sq)...{ sq->base=(char*)malloc(STACK_INIT_SIZE*sizeof(char)); if(!sq->base)exit(OVERFLOW); sq->top=sq->base; sq->stacksize=STACK_INIT_SIZE; return OK;}int initStack(sqStack* sq)...{ sq->base=(int*)malloc(STACK_INIT_SIZE*sizeof(int)); if(!sq->base)exit(OVERFLOW); sq->top=sq->base; sq->stacksize=STACK_INIT_SIZE; return OK;}char GetTop(SqStack* sq,char* e)...{ if(sq->base==sq->top)return ERROR; *e=*(sq->top-1); return (*e);} //GetTopint getTop(sqStack* sq,int* e)...{ if(sq->base==sq->top)return ERROR; *e=*(sq->top-1); return (*e);} //getTopint Push(SqStack* sq,char e)...{ if(sq->top-sq->base>=sq->stacksize)
...{ sq->base=(char*)realloc(sq->base,(sq->stacksize+STACKINCREMENT)*sizeof(char)); if(!sq->base)exit(OVERFLOW); sq->top=sq->base+sq->stacksize; sq->stacksize+=STACKINCREMENT;
} *sq->top++=e; return OK;}//Pushint push(sqStack* sq,int e)...{ if(sq->top-sq->base>=sq->stacksize) ...{ sq->base=(int*)realloc(sq->base,(sq->stacksize+STACKINCREMENT)*sizeof(int)); if(!sq->base)exit(OVERFLOW); sq->top=sq->base+sq->stacksize; sq->stacksize+=STACKINCREMENT; } *sq->top++=e; return OK;}//pushint Pop(SqStack* sq,char* e)...{ if(sq->base==sq->top)return ERROR; *e=*--sq->top; return OK;}//Popint pop(sqStack* sq,int* e)...{ if(sq->base==sq->top)return ERROR; *e=*--sq->top; return OK;}//popchar Compare(char t1,char t2) //判断两个运算符的优先关系...{ char f; switch(t2) ...{ case '+': case '-':if(t1=='('||t1=='#') f='<'; else f='>'; break; case '*': case '/':if(t1=='*'||t1=='/'||t1==')') f='>'; else f='<'; break; case '(':if(t1==')') ...{ printf("ERROR1 "); exit(ERROR); } else f='<'; break; case ')':switch(t1) ...{ case '(':f='='; break; case '#':printf("ERROR2 "); exit(ERROR); default: f='>'; } break; case '#':switch(t1) ...{ case '#':f='='; break; case '(':printf("ERROR3 "); exit(ERROR); default: f='>'; } }/**//*switch(t2)*/ return f;}/**//*Compare*/int In(char c) //判断c是否为运算符...{ switch(c) ...{ case'+': case'-': case'*': case'/': case'(': case')': case'#