12.28作业
0.
int a,b,c;
a=1;b=1;c=1;
a=++b + ++c;
printf("\n%d,%d,%d",a,b,c);//a=4,b=2,c=2
a=b++ + c++;
printf("\n%d,%d,%d",a,b,c);//a=4,b=3,c=3
a=++b || c++;(逻辑运算符规则)
printf("\n%d,%d,%d",a,b,c);//a=1,b=4,c=3
a=b-- && --c;
printf("\n%d,%d,%d",a,b,c);//a=1,b=3,c=2
a=b>c?b++:c++;
printf("\n%d,%d,%d",a,b,c);//a=3,b=4,c=2
（红字体是答案）
1.
#include
int main(int argc, const char *argv[])
{
double a, b;
char c;
scanf(“%lf%c%lf”,&a,&c,&b);
switch(c)
{
case'+':printf("%f\n",a+b);break;
case'-':printf("%f\n",a-b);break;
case'*':printf("%f\n",a*b);break;
case'/':printf("%f\n",a/b);break;
default:printf("输出错误\n");
}
}
2.
#include
int main(int argc, const char *argv[])
{
int a,b,c;
scanf(“%d%d%d”,&a,&b,&c);
if(a+b>c&&a+c>b&&b+c>a)
{
if(a==b||b==c||a==c)
{
if(a==b&&b==c)
{
printf(“是等边三角型\n”);
}
else
{
printf(“是等腰三角型\n”);
}
}
else
{
printf(“是普通三角型\n”);
}
else
{
printf(“不是三角型\n”);
}
return 0；
}
3.
#include
int main(int argc, const char *argv[])
{
int num=0,ge=0,shi=0,bai=0;
scanf(“%d”,&num);
ge=a%10;
shi=a%100/10;
bai=a/100;
if(num>=0&&num<10)
{
if(a/2==0)
{
printf(“输入的数是一位数且是偶数\n”);
}
else
{
printf(“输入的数是一位数且是奇数\n”);
}
}
if(num>=10&&num<100)
{
if(ge%shi==0)
{
printf(“输入的数是两位数且个位数能被十位数整除\n”);
}
else
{
printf(“输入的数是两位数且个位数不能被十位数整除\n”);
}
if(num>=100&&num<1000)
{
if(ge*ge*ge+bai*bai*bai+shi*shi*shi==a)
{
printf("是百位数且是水仙花数\n");
}
else
{
printf("是百位数且不是水仙花数\n");
}
}
return 0；
}
4.
#include
int main(int argc, const char *argv[])
{
char ch;
scanf(“%c”,&a);
if((ch>='a'&&ch<='z')||(ch>='A'&&ch<='Z'))
{
if(ch>='A'&&ch<='Z')
{
putchar(ch+32);
}
if(ch>='a'&&ch<='z')
{
putchar(ch-32);
}
else
{
printf(“不是字母\n”);
}
}
return 0;
}
5.
#include
int main(int argc, const char *argv[])
{
int day=0,year=0,m=0;
scanf("%d%d%d",&year,&m,&day);
switch(m)
{
case 12:{
if(day>31)
{
printf("输入错误\n");
}
day =day+30;break;}
case 11:
day =day+31;break;
case 10:
day =day+30;break;
case 9 :
day =day+31;break;
case 8 :
day =day+31;break;
case 7 :
day =day+30;break;
case 6 :
day =day+31;break;
case 5 :
day =day+30;break;
case 4 :
day =day+31;break;
case 3 :
day =day+28;break;
case 2:
day =day+31;break;
case 1 :
day=day;break;
}
if(year%4==0&&year%100!=0||year%400==0)
{
if(m>2&&m<=12)
{
day+=1;
printf("是闰年且是这一年的第%d天\n",day);
}
else if(m>0&&m<=2)
{
printf("是闰年且这是这一年的第%d\n",day);
}
else
printf("输入错误\n");
}
else
{
if(m>0&&m<=12){
printf("是平年且这一年的第%d\n",day);
}
else
{
printf("输入错误\n");
}
}
return 0;
}