上周C语言作业

小学生计算器：

实现了基本的加减乘除（题目普遍简单） 话说C语言的置随机数种子还真是怪胎啊~

#include <stdio.h>
#include <time.h>
int kind,a,b,res,num;
//double c,d;
void content()
{
    srand((int)time(0));
    kind = rand()%4;
    if(kind==0)
    {
        a = rand()%50+1;
        b = rand()%50+1;
        res = a+b;
        printf("%d+%d=",a,b);
    }
        if(kind==1)
        {
            a = rand()%100+1;
            b = rand()%100+1;
            while(a<b)
            {
                a = rand()%100+1;
                b = rand()%100+1;
            }

            res = a-b;
            printf("%d-%d=",a,b);
        }
        if(kind==2)
        {
            a = rand()%11;
            b = rand()%11;
            res = a*b;
            printf("%dX%d=",a,b);
        }
        if(kind==3)
        {
            a = rand()%100;
            b = rand()%99+1;
            while(a%b!=0||a==0)
            {
                a = rand()%100;
                b = rand()%100;
            }
            res = a/b;
            printf("%d÷%d=",a,b);
        }

}
int main()
{
    printf("小学生数学计算器\n");
    content();
    while(scanf("%d",&num)!=EOF)
    {
        if(num==res)
            printf("正确\n");
        else
            printf("错误\n");
        content();
    }
}

不同阶段税收计算：

#include <stdio.h>
int main()
{
    double dSalary,dNetlncome=0;
    printf("请输入您本月的收入总额\n");
    scanf("%lf",&dSalary);
    if(dSalary-3500>80000)
        dNetlncome = (dSalary-3500)*0.45 - 13505;
    else if(dSalary-3500>55000 && dSalary-3500<=80000)
        dNetlncome = (dSalary-3500)*0.35 - 5505;
    else if(dSalary-3500>35000 && dSalary-3500<=55000)
        dNetlncome = (dSalary-3500)*0.30 - 2755;
    else if(dSalary-3500>9000 && dSalary-3500<=35000)
        dNetlncome = (dSalary-3500)*0.25 - 1005;
    else if(dSalary-3500>4500 && dSalary-3500<=9000)
        dNetlncome = (dSalary-3500)*0.20 - 555;
    else if(dSalary-3500>1500 && dSalary-3500<=4500)
        dNetlncome = (dSalary-3500)*0.1 - 105;
    else if(dSalary-3500>0 && dSalary-3500<=1500)
        dNetlncome = (dSalary-3500)*0.03;
    printf("您本月应缴个人所得税 %.2lf 元，税后收入是 %.2lf元。 \n",dNetlncome,dSalary-dNetlncome);
    printf("依法纳税，共享繁荣，谢谢使用！\n");
    return 0;
}

回文数：

//输入一个正整数，判断是否为回文数 如1221 12321
#include <stdio.h>
int pf(int i)
{
    int num=1;
    i--;
    while(i>0)
    {
        num*=10;
        i--;
    }
     return num;
}
int main()
{
    int number,number2,number3,tempnum,newnum=0;
    scanf("%d",&number);
    number3 = number2 = number;
    int i=0,j=0;
    while(number/10>0)
    {
        i++;
        number/=10;
    }
    i++;
    j = i;
    while(i>0)
    {

        tempnum = number2/pf(i);
        number2 -= pf(i)*tempnum;

        newnum += tempnum*pf(j+1-i);

        i--;
    }
    if(newnum==number3)
        printf("是回文数");
    else
        printf("不是回文数");
    return 0;
}