自己编写的C语言四则运算

Question

#include<stdio.h>
#include<string.h>
void main()
{
float result=0,n[4]={0},save[4]={0};
int i=0,m=0,p=0,chars[3];
char input[16];
printf("请输入算数表达式：\n");
gets(input);
do //将字符串转换为数字
{
if(input[p]>='0'&&input[p]<='9')
n[i]=10*n[i]+(input[p]-'0');
else
i++;
p++;
}
while(input[p]!='=');
for(i=0;i<10;i++) //记录运算符
{
switch(input[i])
{
case'+': chars[m]=1; m++; break;
case'-': chars[m]=2; m++; break;
case'*': chars[m]=3; m++; break;
case'/': chars[m]=4; m++; break;
default: continue;
}
}
i=0;
for(m=0;m<3;m++)
{
if(chars[m]==1)
{
save[i]=n[m];
i++;
m++;
continue;
}
else if(chars[m]==2)
{
save[i]=-n[m];
i++;
m++;
continue;
}
else if(chars[m]==3)
result=result+n[m]*n[m+1];
else
result=result+n[m]/n[m+1];
}
for(i=0;i<4;i++)
result+=save[i];
printf("计算结果为：%f",result);
}
这是我自己写的代码，不知道哪里出错了。。。

Answer 1

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int add(int num1,int num2)//加法
{
return num1+num2;
}
int subtraction(int num1,int num2)//减法
{
return num1-num2;
}
int mul(int num1,int num2)//乘法
{
return num1*num2;
}
float divis(int num1,int num2)//除法
{
return ((int)(((float)num1/num2)*100+0.5))/100.0;
}
int main()
{
int type = -1;
int data = -1;
int choice,num1,num2,results;
float div_result;
int right = 0;
int wrong = 0;
char ch;
printf("欢迎进入四则运算题，现在开始爆发你的小宇宙吧！\n");
srand((unsigned int)time(NULL));
while(1)
{
printf("请选择运算类型：1.加法 2.减法 3.乘法 4.除法(保留两位小数)\n");
scanf("%d",&choice);
printf("请选择位数：1.一位数 2.两位数\n");
scanf("%d",&data);
switch (choice)
{
case 1:
if(data == 1)
{
num1 = rand()%10;
num2 = rand()%10;
printf("%d + %d=__?__\n",num1,num2);
scanf("%d",&results);
if(results == add(num1,num2))
{
printf("回答正确！\n");
right++;
}
else
{
printf("回答错误！\n");
wrong++;
}
printf("是否继续？y/n\n");
getchar();
scanf("%c",&ch);
if(ch == 'y')
break;
else if(ch == 'n')
goto end;
}
else if (data == 2)
{
num1 = rand()%100;
num2 = rand()%100;
printf("%d + %d=__?__\n",num1,num2);
scanf("%d",&results);
if(results == add(num1,num2))
{
printf("回答正确！\n");
right++;
}
else
{
printf("回答错误！\n");
wrong++;
}
printf("是否继续？y/n\n");
getchar();
scanf("%c",&ch);
if(ch == 'y')
break;
else if(ch == 'n')
goto end;
}
break;
case 2:
if(data == 1)
{
num1 = rand()%10;
num2 = rand()%10;
printf("%d - %d=__?__\n",num1,num2);
scanf("%d",&results);
if(results == subtraction(num1,num2))
{
printf("回答正确！\n");
right++;
}
else
{
printf("回答错误！\n");
wrong++;
}
printf("是否继续？y/n\n");
getchar();
scanf("%c",&ch);
if(ch == 'y')
break;
else if(ch == 'n')
goto end;
}
else if (data == 2)
{
num1 = rand()%100;
num2 = rand()%100;
printf("%d - %d=__?__\n",num1,num2);
scanf("%d",&results);
if(results == subtraction(num1,num2))
{
printf("回答正确！\n");
right++;
}
else
{
printf("回答错误！\n");
wrong++;
}
printf("是否继续？y/n\n");
getchar();
scanf("%c",&ch);
if(ch == 'y')
break;
else if(ch == 'n')
goto end;
}
break;
case 3:
if(data == 1)
{
num1 = rand()%10;
num2 = rand()%10;
printf("%d * %d=__?__\n",num1,num2);
scanf("%d",&results);
if(results == mul(num1,num2))
{
printf("回答正确！\n");
right++;
}
else
{
printf("回答错误！\n");
wrong++;
}
printf("是否继续？y/n\n");
getchar();
scanf("%c",&ch);
if(ch == 'y')
break;
else if(ch == 'n')
goto end;
}
else if (data == 2)
{
num1 = rand()%100;
num2 = rand()%100;
printf("%d * %d=__?__\n",num1,num2);
scanf("%d",&results);
if(results == mul(num1,num2))
{
printf("回答正确！\n");
right++;
}
else
{
printf("回答错误！\n");
wrong++;
}
printf("是否继续？y/n\n");
getchar();
scanf("%c",&ch);
if(ch == 'y')
break;
else if(ch == 'n')
goto end;
}
break;
case 4:
if(data == 1)
{
num1 = rand()%10;
num2 = rand()%10+1;
printf("%d / %d=__?__\n",num1,num2);
scanf("%f",&div_result);
if(div_result == divis(num1,num2))
{
printf("回答正确！\n");
right++;
}
else
{
printf("回答错误！\n");
wrong++;
}
printf("是否继续？y/n\n");
getchar();
scanf("%c",&ch);
if(ch == 'y')
break;
else if(ch == 'n')
goto end;
}
else if (data == 2)
{
num1 = rand()%100;
num2 = rand()%100+1;
printf("%d / %d=__?__\n",num1,num2);
scanf("%f",&div_result);
if(div_result == divis(num1,num2))
{
printf("回答正确！\n");
right++;
}
else
{
printf("回答错误！\n");
wrong++;
}
printf("是否继续？y/n\n");
getchar();
scanf("%c",&ch);
if(ch == 'y')
break;
else if(ch == 'n')
goto end;
}
break;
default :
printf("输入错误！\n");
break;
}
}
end:
printf("回答正确%d题，回答错误%d题\n",right,wrong);
printf("\n====================谢谢光临====================！\n");
system("pause");
return 0;
}
//注意除法是采用四舍五入的，有什么不明白的再问吧，望采纳！

Answer 2

算法不行，你既然要写的不是一个简简单单实现一次计算的计算器，而是能对长表达式串（如1+4*3这种）处理的程序，那么我建议你去了解一下什么是逆波兰式，栈，再来写。本回答被提问者采纳