施润行160809301（作业3）

#include<stdio.h>
int main()
{
    char grade;
    printf("请输入等级:");
    scanf("%c",&grade);
    switch(grade)
        {
            case'A':
               printf("90-100");
               break;
            case'B':
               printf("80-89");
               break;
            case'C':
               printf("70-79");
               break;
            case'D':
               printf("60-69");
               break;
            case'E':
               printf("0-59");
                break;
            default: 
               printf("输入错误");
                 break;
        }
    return 0;    
}

#include<stdio.h>
int main()
{
    int a=100;
    int b;
    printf("%d",b=5*(a-32)/9);
    return 0;
}

#include<stdio.h>
int main()
{
    int a=3;
    int b;
    printf("%d",b=(10*a*a)/2);
    return 0;
    
}

#include<stdio.h>
int main()
{
    int a=152;
    int b;
    int c;
    int d;
    b=a%10;
    c=(a/10)%10;
    d=a/100;
    printf("个位数字的值为%d
",b);
    printf("十位数字的值为%d
",c);
    printf("百位数字的值为%d
",d);
    return 0;
} 

#include<stdio.h>
#include<math.h>
int main()
{ 
double x, y;
 printf("请输入一个值：");
 scanf("%lf", &x);
    if (x>=0)
     y = pow(x,0.5);
   else
     y = pow(x+1,2)+2*x+1/x;
 printf("对应y的值是：%.2f",y);
 return 0;
}

#include<stdio.h>
#include<math.h>
int main()
{
    int y,m;
    double r,i;
    printf("请输入存期");
    scanf("%d",&y);
    printf("请输入存款金额");
    scanf("%d",&m);
    printf("请输入年利率");
    scanf("%lf",&r); 
    i=m*pow(1+r,y)-m;
    printf("利息为%f",i);
    return 0;
} 

#include<stdio.h>
int main()
{
    double x;
    double y;
    scanf("%lf",&x);
    if(x<=50)
    y=0.53*x;
    else
    y=0.53*50+(x-50)*0.58;
    printf("f(x)=%f",y);
    return 0;
}

#include<stdio.h>
int main()
{
    printf("   * * * * * * * * * *
");
    printf("    * * * * * * * * *
");
    printf("     * * * * * * * *
");
    printf("      * * * * * * *
");
    printf("       * * * * * *
");
    printf("        * * * * *
");
    printf("         * * * *
");
    printf("          * * *
");
    printf("           * *
");
    printf("            *
");
    return 0; 
}

#include<stdio.h>//1.三角形
int main()
{
    
    printf("*
");
    printf("**
");
    printf("***
");
    printf("****
");
    printf("*****
");
    printf("******
");
    printf("*******
");
    printf("********
");
    printf("*********
");
    printf("**********
");
    return 0;
    
}

#include<stdio.h>
int main()
{
    printf("**********
");
    printf("**********
");
    printf("**********
");
    printf("**********
");
    printf("**********
");
    printf("**********
");
    printf("**********
");
    printf("**********
");
    printf("**********
");
    printf("**********
");
}