作业二

1这题要注意int和double的使用

#include<stdio.h>
int main(void)
{
int num1,num2,a,b,c,e;
double d;
printf("Enter num1 and num2:");
scanf("%d%d",&num1,&num2);
a=num1+num2;
b=num1-num2;
c=num1*num2;
d=num1/num2;
e=num1%num2;
printf("h=%d,c=%d,j=%d,s=%Lf,y=%d\n",a,b,c,d,e);
return 0;
}

3

#include<stdio.h>
int main(void)
{
    int i,n;
    double x,y;
    y=1;

    printf("Enter n,x:");
    scanf("%d%Lf",&n,&x);
    for(i=1;i<=n;i++)
    y=y*x;
    
    printf("y=%.3f\n",y);
    return 0;
}

4

#include<stdio.h>
int main()
{
    int i,m,n;
    double y;
    y=0;

    printf("Enter m,n:");
    scanf("%d%d",&m,&n);

    for(i=m;i<=n;i++)
    y=y+(i*i+1/i);
    printf("y=%.3f\n",y);
    return 0;
}

5 flag的使用

#include<stdio.h>
int main()
{
    int n,flag;
    double item,sum,i;

    printf("Enter n:");
    scanf("%d",&n);
    flag=1;    
    sum=0;

    for(i=1;i<=n;i++){    
        item=flag*i/(2*i-1);  
        sum=sum+item;
        flag=-flag;
    }

    printf("sum=%f\n",sum);
    return 0;
}

6

#include<stdio.h>
#include<math.h>
int main(void)
{
    int i,loan,month,money;
    double rate,m,n;

    printf("Enter loan,rate:");
    scanf("%d%Lf",&loan,&rate);

    for(i=5;i<=30;i++){
    month=i*12;
    m=rate*pow(1+rate,month);
    n=pow(1+rate,month)-1;
    money=loan*(m/n);
    printf("i=%d,money=%d\n",i,money);
    }

    return 0;
}

7

#include<stdio.h>
#include<math.h>
int main(void)
{
    int n,i;
    double m,sum;

    printf("Enter n:");
    scanf("%d",&n);
    sum=0;

    for(i=1;i<=n;i++){
    m=pow(2,i);
    sum=sum+m;
    }
    printf("sum=%.3f\n",sum);
    return 0;
}