C++實現四則混合運算計算器
阿新 • • 發佈:2020-11-26
本文例項為大家分享了C++實現四則混合運算的計算器,供大家參考,具體內容如下
計算器是帶括號的四則運算實際上利用的是棧後進先出的原則
轉換思想:
#define _CRT_SECURE_NO_WARNINGS 1 #include"stdio.h" #include"stdlib.h" #include"string.h" #define maxsize 1024 typedef struct { float data[maxsize]; int top; }Stack1; void Initstack1(Stack1 *S) { S = (Stack1*)malloc(sizeof(Stack1)); S->top = -1; } int Push1(Stack1 *S,float ch) { if (S->top == maxsize - 1) return 0; else { S->top++; S->data[S->top] = ch; return 1; } }//入棧Push int Pop1(Stack1 *S,float ch) { if (S->top == -1) printf("棧上溢位!\n"); else ch = S->data[S->top]; S->top--; return 1; }//出棧 typedef struct { char data[maxsize]; int top; }Stack2; void Initstack2(Stack2 *S) { S = (Stack2*)malloc(sizeof(Stack2)); S->top = -1; } int Push2(Stack2 *S,char ch) { if (S->top == maxsize - 1) return 0; else { S->top++; S->data[S->top] = ch; return 1; } }//入棧Push int Pop2(Stack2 *S,char ch) { if (S->top == -1) printf("棧上溢位!\n"); else ch = S->data[S->top]; S->top--; return 1; }//出棧 int Comop(char ch) //判斷是否是運算子 { switch (ch) { case'+': case'-': case'*': case'/': case'(': case')': case'#': return 1; default: return 0; } }//判斷ch是否為運算子 char Prior[7][7] = { // 運算子優先順序表 // '+' '-' '*' '/' '(' ')' '#' /*'+'*/{ '>','>','<','>' },/*'-'*/{ '>',/*'*'*/{ '>',/*'/'*/{ '>',/*'('*/{ '<','=','< ' },/*')'*/{ '>',' ',/*'#'*/{ '<','> ','=' },}; int Opid(char op1) { switch (op1) { case'+':return 0; case'-':return 1; case'*':return 2; case'/':return 3; case'(':return 4; case')':return 5; case'#':return 6; default:return -123456; } } char Precede(char op1,char op2) //優先順序比較 { int a,b; a = Opid(op1); b = Opid(op2); return(Prior[a][b]); } float Operation(float a,char op,float b) { switch (op) { case '+': return b + a; case '-': return b - a; case '*': return b * a; case '/': return b / a; default: return -123456; } } void CreateExpression(char *exp) { if (exp == NULL) { exit(1); } scanf("%s",exp); } void TransmitExpression(char *exp,char postexp[]) //中綴表示式轉換字尾表示式 { Stack2 FZ; Initstack2(&FZ); int i = 0; char x; FZ.top = -1; Push2(&FZ,'#'); FZ.data[FZ.top] = '#'; while (*exp != '\0') { if (!Comop(*exp)) { while (*exp >= '0'&&*exp <= '9')//讀取一個數字串 { postexp[i++] = *exp; exp++; } postexp[i++] = '#'; } else switch (Precede(FZ.data[FZ.top],*exp)) { case'<': Push2(&FZ,*exp); exp++; break; case'=': x = FZ.data[FZ.top]; Pop2(&FZ,x); exp++; break; case'>': postexp[i++] = FZ.data[FZ.top]; x = FZ.data[FZ.top]; Pop2(&FZ,x); break; } } while (FZ.data[FZ.top] != '#') { postexp[i++] = FZ.data[FZ.top]; x = FZ.data[FZ.top]; Pop2(&FZ,x); } postexp[i] = '\0'; } float EvaluateExpression(char *postexp) //字尾表示式的計算 { Stack1 SZ; Initstack1(&SZ); float a,b,d; SZ.top = -1; while (*postexp != '\0') { switch (*postexp) { case'+': case'-': case'*': case'/': a = SZ.data[SZ.top]; Pop1(&SZ,a); b = SZ.data[SZ.top]; Pop1(&SZ,b); Push1(&SZ,Operation(a,*postexp,b)); break; default: d = 0; while (*postexp >= '0'&&*postexp <= '9') { d = 10 * d + *postexp - '0'; postexp++; } Push1(&SZ,d); SZ.data[SZ.top] = d; break; } postexp++; } return(SZ.data[SZ.top]); } int Error(char *exp) //錯誤表示式判斷 { int i = 0; while (exp[i] != '\0') { if ( ((exp[i] == '+' || exp[i] == '-' || exp[i] == '*' || exp[i] == '/') && (exp[i + 1] == ')')) || ((exp[i] == '+' || exp[i] == '-' || exp[i] == '*' || exp[i] == '/') && (exp[i - 1] == '(')) || (exp[i] == ')'&&exp[i + 1] == '(') || (exp[i] == '('&&exp[i + 1] == ')') || ((exp[i] == ')') && exp[i + 1] >= '0'&&exp[i + 1] <= '9') || (exp[i] >= '0'&&exp[i] <= '9'&&exp[i + 1] == '(') || (exp[0] == '+' || exp[0] == '-' || exp[0] == '*' || exp[0] == '/' || exp[0] == ')') || ((exp[i] == '+' || exp[i] == '-' || exp[i] == '*' || exp[i] == '/') && (exp[i + 1] == '+' || exp[i + 1] == '-' || exp[i + 1] == '*' || exp[i + 1] == '/')) || (exp[i] == '/'&&exp[i + 1] == '0') ) return 1; else if (exp[i] == '\0') return 0; i++; } return 0; } void menu() { printf("\t\t--------------------------------------------\n"); printf("\t\t| 計算器 |\n"); printf("\t\t| ---------------- |\n"); printf("\t\t| | | |\n"); printf("\t\t| ---------------- |\n"); printf("\t\t| 1 2 3 + |\n"); printf("\t\t| 4 5 6 - |\n"); printf("\t\t| 7 8 9 * |\n"); printf("\t\t| 0 ( ) / |\n"); printf("\t\t--------------------------------------------\n"); printf("\t\t 請輸入你要進行的操作:\n"); printf("\t\t a表示式求值 b清空 c退出\n"); } void clear() { system("cls"); menu(); } void Quit() { system("cls"); exit(1); } void main() { char c; char exp[maxsize]; char postexp[maxsize] = { 0 }; menu(); while (1) { scanf("%c",&c); switch (c) { case 'a': sr : printf("請輸入要計算的表示式:\n"); CreateExpression(exp); if (!Error(exp)) { TransmitExpression(exp,postexp); printf("字尾表示式為:%s\n",postexp); printf("表示式結果為:%s=",exp); printf("%g\n",EvaluateExpression(postexp)); break; } else if (Error(exp)) { printf("您輸入的表示式有誤!\n"); goto sr;//goto語句在迴圈體裡進行跳轉 } case'b': clear(); break; case'c': Quit(); break; } } system("pause"); }
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支援我們。