数据结构运算符的优先级.docx

#include#include#include #define STACK_INIT_SIZE 100#define STACKCREMENT 10#define OPSIZE 7#define ERROR 0#define OK 1#define OVERFLOW -1unsigned char Prior77 = / 算符间的优先关系 , , , , , , ,=S.stacksize) S.base=(float *)realloc(S.base,(S.stacksize+STACKCREMENT)*sizeof(float); if(!S.base) exit(OVERFLOW); S.top=S.base+S.stacksize; S.stacksize+=STACKCREMENT; *S.top+=e; return OK; /出栈 int Pop(SqStack &S,float &e)if(S.base=S.base) return ERROR; e=*-S.top; return OK;/运算操作 float Operate(float a,char theta,float b)switch(theta)case +:return a+b;case -:return b-a;case *:return a*b;case /:return b/a;default:return 0;/判断是否为运算符 int In(char c,char *OP)bool Find=false;for(int i=0;iOPSIZE;i+) if(c=OPi) Find=true; return Find;/运算符优先关系比较int ReturnOpOrd(char op,char* TestOp) int i; for(i=0; i OPSIZE; i+) if (op = TestOpi) return i; return 0;char Precede(char theta,char c) return PriorReturnOpOrd(theta,OP)ReturnOpOrd(c,OP);/ 算术表达式求值的算符优先算法。/ 设OPTR和OPND分别为运算符栈和运算数栈，OP为运算符集合。char EvaluateExpression()char TempData20; float Data,a,b; char theta,c,x,Dr2;SqStack OPND; / 运算数栈SqStack OPTR; / 运算符栈InitStack(OPTR);Push(OPTR,#);InitStack(OPND);c=getchar();while(c!=#|GetTop(OPTR)!=#)if(!In(c,OP) / 不是运算符则进栈Push(OPND,c);c=getchar();else switch(Precede(GetTop(OPTR),c) case :Pop(OPTR,theta); Pop(OPND,b); Pop(OPND,a); Push(OPND,Operate(a,theta,b); break; return GetTop(OPND);int ma