输入 ：后缀表达式（可带浮点数）
输出：double型的计算结果
代码：
#include#include #include #define ElemType double#define Stack_Init_Size 100#define Increase_Size 10#define MaxBuffer 10typedef struct sqStack{ ElemType *top; ElemType *base; int initSize;}sqStack;typedef struct sqStack *LinkStack;//初始化void InitStack( sqStack *s ){ s->base = (LinkStack)malloc(Stack_Init_Size * sizeof(ElemType)); if(!s->base) { printf("存储空间分配失败······\n"); return; } s->top = s->base; s->initSize = Stack_Init_Size;}//进栈void Push(sqStack *s,ElemType e){ if(s->top - s->base >= s->initSize - 1) { s->base = (LinkStack)realloc(s->base,(s->initSize + Increase_Size) * sizeof(ElemType)); //第一个s->base是增加后的存储空间块的地址，第二个是增加空间之前的存储空间块地址，后面是增加过的存储空间块的大小 if(!s->base) { printf("增加存储空间失败······\n"); return; } s->initSize = Increase_Size + Stack_Init_Size; } *(s->top) = e; (s->top)++;}//出栈void Pop(sqStack *s,ElemType *e){ if(s->top == s->base) { printf("栈已空，无法进行出栈操作······\n"); return; } s->top--; *e = *s->top;}//求栈的长度int StackLen(sqStack s){ return (s.top - s.base);}//逆波兰计算器：输入逆波兰式（后缀表达式）输出结果int main(){ int i = 0,j,len; double m,n,t; char c; struct sqStack s; char str[MaxBuffer]; InitStack(&s); printf("请输入您要计算的后缀表达式，按Enter键结束（两个不同的字符之间用空格隔开）：\n"); scanf("%c",&c); while(c != '\n') { while( (c >= '0'&&c <= '9') || c == '.') { str[i] = c; i++; // str[i] = '\0'; if(i >= 10) { printf("\n输入的数字过大导致出错！！！\n"); return -1; } scanf("%c",&c); if( c == ' ') { t = atof(str); // printf("\nt is %f\n",t); Push(&s,t); i = 0; for(j = 0;j < MaxBuffer;j++) { str[j] = '\0'; } break; } } switch( c ) { case '+': Pop(&s,&m); Pop(&s,&n); Push(&s,n+m); break; case '-': Pop(&s,&m); Pop(&s,&n); Push(&s,n-m); break; case '*': Pop(&s,&m); Pop(&s,&n); Push(&s,n*m); break; case '/': Pop(&s,&m); Pop(&s,&n); if( m == 0) { printf("\n除数为0，出错！！！\n"); return -1; } else { Push(&s,n/m); break; } } scanf("%c",&c); } Pop(&s,&t); printf("\n最终的计算结果为：%f \n",t); return 0;}
posted on 2014-12-15 12:48 阅读( ...) 评论( ...)