简单的四则运算

#include<stdio.h>
#include<stdlib.h>
int jiafa(int x, int y)
{
int a = 0;
int b = 0;
int c = 0;
printf("请输入需要加法的数字 ");
scanf_s("%d%d", &a,&b);
printf("您输入的两个数分别为%d %d",a,b);
c = a + b;
printf("加法结果为%d", c);
return c;
}
int jianfa(int x, int y)
{
int a = 0;
int b = 0;
int c = 0;
int f = 0;
printf("请输入需要减法的数字 ");
scanf_s("%d%d", &a, &b);
printf("您输入的两个数分别为%d %d", a, b);
if (a > b)
{
c = a - b;
b = c;
printf("减法结果为%d", b);
}
else
{
c = a - b;
b = -c;
printf("减法结果为%d",- b);
}

return b;
}
int chengfa(int x, int y)
{
int a = 0;
int b = 0;
int c = 0;
printf("请输入需要乘法的数字 ");
scanf_s("%d%d", &a, &b);
printf("您输入的两个数分别为%d %d", a, b);
c = a * b;
printf("乘法结果为%d", c);
return c;
}
char chufa(int x, int y)
{
int a = 0;
int b = 0;
int c = 0;
printf("请输入需要除法的数字 ");
scanf_s("%d%d", &a, &b);
printf("您输入的两个数分别为%d %d", a, b);
c = a /b;
printf("除法结果为%d", c);
return c;
}
void main()
{
int x = 0;
int y = 0;
int a = 0;
printf(" 欢迎进入简单四则运算系统 ");
printf(" 1.减法运算 ");
printf(" 2.加法运算 ");
printf(" 3.乘法运算 ");
printf(" 4.除法运算 ");
scanf_s("%d", &a);
switch (a)
{
case 1:jiafa(x, y);
break;
case 2:jianfa(x, y);
break;
case 3:chengfa(x, y);
break;
case 4:chufa(x, y);
break;
}

}

程序是简单的被动输入四则运算。。。。因实力有限希望在以后的学习中更加努力做出更好的程序。