用栈实现括号匹配的检验 修改

用栈实现括号匹配的检验修改(2008-11-14 19:06:31)标签：c语言编程turbo c2.0环境实现栈括号匹配it 分类：C语言编程例子数据结构C 语言版括号匹配问题是编译程序时经常遇到的问题，用以检测语法是否有错。

本文前些天写的用栈实现括号匹配的检验的代码中，其中用了更少变量的代码二有些错误，使得结果总是match，经过修改，现将正确的代码写出，如下#include<stdlib.h>#include<stdio.h>#define OVERFLOW -1#define OK 1#define ERROR 0#define STACK_INIT_SIZE 100#define STACKINCREMENT 10#define NULL 0typedef char SElemType;typedef int Status;typedef struct{SElemType *base;SElemType *top;int stacksize;}SqStack;Status InitStack(SqStack *S){(*S).base=(SElemType *)malloc(STACK_INIT_SIZE * sizeof(SElemType));if(!(*S).base) exit(OVERFLOW);(*S).top=(*S).base;(*S).stacksize=STACK_INIT_SIZE;return OK;}Status DestroyStack(SqStack *S){free((*S).base);(*S).base=NULL;(*S).top=NULL;(*S).stacksize=0;return OK;}Status StackEmpty(SqStack *S){if((*S).top==(*S).base) return OK;else return ERROR;}Status Push(SqStack *S,SElemType e){if((*S).top-(*S).base>=(*S).stacksize){(*S).base=(SElemType *)realloc((*S).base,((*S).stacksize+STACKINCREMENT)*sizeof(SElemType));if(!(*S).base) exit(OVERFLOW);(*S).top=(*S).base+(*S).stacksize;(*S).stacksize+=STACKINCREMENT;}*S->top++=e;return OK;}Status Pop(SqStack *S,SElemType *e){if((*S).top==(*S).base) return ERROR;*e=*--S->top;return OK;}main(){SqStack S;SElemType elem;char e,a[20];int i=0;int flag=1;clrscr();if( InitStack(&S))printf("kongjian yijing zhunbei hao!\n");else printf("there is not enough room!\n");printf("input the kuohao (<=20 ge) and press '#' to show the end:\n");do{scanf("%c",&e);a[i]=e;i++;}while(e!='#');i=0;e=a[i];while(e!='#'&&flag){ switch(e){case '(': Push(&S,e); break;case '[': Push(&S,e);break;case '{': Push(&S,e);break;case ')':if(!StackEmpty(&S)){Pop(&S,&e);if(e!='(')flag=0;}else flag=0;break;case ']': if(!StackEmpty(&S)){ Pop(&S,&e);if(e!='[') flag=0;}else flag=0;break;case '}':if(!StackEmpty(&S)){ Pop(&S,&e);if(e!='{') flag=0;}else flag=0;break;}i++;e=a[i];}if(!StackEmpty(&S)) flag=0;if(flag)printf("MATCH!\n");else printf("MIS MA TCH!\n");if(DestroyStack(&S))printf("the stack is already destroyed!\n");else printf("destroy error!\n");printf("press any key to continue!\n");getch();}表达式求值算符优先法 C 语言编程(2008-11-14 19:10:49)标签：if 运算符表达式数据结构c语言turbo c2.0 分类：C语言编程例子数据结构C语言版表达式求值是实现程序设计语言的基本问题之一，也是栈的应用的一个典型例子。

设计一个程序，用算符优先法对表达式求值。

以字符序列的形式从终端输入语法正确的、不含变量的整数表达式//用栈实现表达式求值个位数的混合运算#include<stdlib.h>#include<stdio.h>#define OVERFLOW -1#define OK 1#define TRUE 1#define FALSE 0#define ERROR 0#define STACK_INIT_SIZE 100#define STACKINCREMENT 10#define NULL 0typedef char SElemType;typedef int Status;typedef struct{SElemType *top;SElemType *base;int stacksize;}SqStack;Status InitStack(SqStack *S){(*S).base=(SElemType *)malloc(STACK_INIT_SIZE * sizeof(SElemType)); //开辟空间if(!(*S).base) exit(OVERFLOW); //存储分配失败(*S).top=(*S).base;(*S).stacksize=STACK_INIT_SIZE;return OK;}Status DestroyStack(SqStack *S){free((*S).base);(*S).base=NULL;(*S).top=NULL;(*S).stacksize=0;return OK;}Status StackEmpty(SqStack *S){if((*S).top==(*S).base) return OK;else return ERROR;}Status Push(SqStack *S,SElemType e) //插入为新的栈顶元素{if((*S).top-(*S).base>=(*S).stacksize) //栈满追加存储空间{(*S).base=(SElemType *)realloc((*S).base,((*S).stacksize+STACKINCREMENT)*sizeof(SElemType));if(!(*S).base) exit(OVERFLOW); //存储分配失败(*S).top=(*S).base+(*S).stacksize;(*S).stacksize+=STACKINCREMENT;}*S->top++=e;return OK;}Status Pop(SqStack *S,SElemType *e){if((*S).top==(*S).base) return ERROR;*e=*--S->top;return OK;}int Transfor(char c){ //返回字符c对应优先关系表中的行列号int k;switch(c){ case '+':k=0;break;case '-':k=1;break;case '*':k=2;break;case '/':k=3;break;case '(':k=4;break;case ')':k=5;break;case '#':k=6;break;}return k;}char Precede(char c1,char c2){ //判断c1与c2的位序关系,优先的返回'=',非'<',其他还有'='和' ' int i,j;char a[7][7]={ {'>','>','<','<','<','>','>'},{'>','>','<','<','<','>','>'},{'>','>','>','>','<','>','>'},{'>','>','>','>','<','>','>'},{'<','<','<','<','<','=',''},{'>','>','>','>','','>','>'},{'<','<','<','<','<','','='}};i=Transfor(c1);j=Transfor(c2);return(a[i][j]);}Status In(char c,char OP[]){ //判断字符c 是否算符，是ok非errorint i;for(i=0;i<=6;i++)if(c==OP[i]) return TRUE;return FALSE; //全判定完还没有则返回false}char Operate(char a,SElemType theta,char b){ //数值计算int z;switch(theta){ case '+':z=a+b;break;case '-':z=b-a;break; //被减数先进栈，故交换所取值case '*':z=a*b;break;case '/':z=b/a;break;}return z;}SElemType GetTop(SqStack *S){ //若栈不空,用e 返回栈顶元素和OK,否则ERRORSElemType e;if((*S).top==(*S).base) return ERROR;e=*((*S).top-1);return e;}main(){ SElemType c,elem; //运算符SqStack OPTR,OPND; //运算符栈和运算数栈int a,b,thera; //运算数int optag=FALSE;char OP[7]={'+','-','*','/','(',')','#'};OPTR.top=NULL;OPTR.base=NULL;OPND.top=NULL;OPND.base=NULL; clrscr();//初始化运算符栈if( InitStack(&OPTR))printf("kongjian OPTR yijing zhunbei hao!\n");else printf("there is not enough room for OPTR!\n");//初始化运算数栈Push(&OPTR,'#');if(InitStack(&OPND))printf("kongjian OPND yijing zhunbei hao!\n");else printf("there is not enough room for OPND!\n");printf("input the expression_r:\n");scanf("%c",&c);elem=GetTop(&OPND);while(c!='#'||GetTop(&OPTR)!='#'){ if(!In(c,OP)) //不是运算符则进操作数栈{ if(optag){Pop(&OPND,&elem);elem=elem*10+c-'0';Push(&OPND,c);}else Push(&OPND,c-'0');optag=TRUE;scanf("%c",&c);} //不是运算符则进栈else{if(!optag&&c=='-')Push(&OPND,0);switch(Precede(GetTop(&OPTR),c)){case '<': //栈顶元素优先权低Push(&OPTR,c);scanf("%c",&c);optag=FALSE;break;case '=': //脱括号并接受下一个字符Pop(&OPTR,&elem);scanf("%c",&c);optag=FALSE;break;case '>': //退栈并将运算结果入栈Pop(&OPTR,&elem);thera=elem;Pop(&OPND,&elem);a=elem;Pop(&OPND,&elem);b=elem;Push(&OPND,Operate(a,thera,b));break;}//switch}}elem=GetTop(&OPND);printf("jisuan jiguo wei : %d\n",elem);if(DestroyStack(&OPTR))printf("stack optr (yunsuanfuzhan) destroyed!\n");else printf("not destroyed!\n");if(DestroyStack(&OPND))printf("stack opnd (caozuoshuzhan) destroyed!\n");else printf("not destroyed!\n");printf("press any key to continue:\n");getch();}实验六：实现串的基本操作（2学时）用堆分配存储表示实现Hstring串类型的最小操作子集的基础上，实现串抽象数据类型的其余基本操作（不使用C语言本身提供的串函数）。