作业 2 分支、循环结构

#include<stdio.h>
int main(void)
{
int num1,num2;
char op;         /*自定义一个字符串类型的变量*/

printf("Type in an expression:");    /*提示输入一个算式*/
scanf("%d%c%d",&num1,&op,&num2);     /*输入一个整数，一个字符，一个整数*/

if(op=='+')            /* 判断字符变量是否为+，若是则进行下行操作。下同 */
printf("=%d\n",num1+num2);
else if(op=='-')
printf("=%d\n",num1-num2);
else if(op=='*')
printf("=%d\n",num1*num2);
else if(op=='/')
printf("=%d\n",num1/num2);
else if(op=='%')
printf("=%d\n",num1%num2);
else
printf("Unknown operator\n");

return 0;
}

#include<stdio.h>
int main(void)
{
int i,n;
double x,y;
y=1;
printf("Enter x and n:");
scanf("%Lf%d",&x,&n);

for(i=1;i<=n;i++){
y=y*x;         /*计算x乘以本身n次*/
}
printf("y=%.2f",y);
return 0;
}

#include<stdio.h>
int main(void)
{
int m,n,i;
double y;
y=0;
printf("Enter m and n:");
scanf("%d%d",&m,&n);

for(i=m;i<=n;i++){
y=y+i*i+1/i;
}
printf("y=%.2f\n",y);

return 0;
}

#include<stdio.h>
int main(void)
{
int i,n,x;
double y;
x=1;
y=0;
printf("Enter n:");
scanf("%d",&n);

for(i=1;i<=n;i++){
y=y+(x*i)/(2*i-1);
x=-x;
}
printf("y=%.2f\n",y);

return 0;
}

#include<stdio.h>
#include<math.h>
int main(void)
{
int year;
double rate,money,loan,x;

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

for(year=5;year<=30;year++){
x=pow(1+rate,12*year);
money=loan*rate*x/(x-1);
printf("year=%d,money=%.2f\n",year,money);
}

return 0;
}

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

printf("Enter n:");
scanf("%d",&n);
y=0;
for(i=1;i<=n;i++){
x=pow(2,i);
y=y+x;
}
printf("y=%.2f\n",y);

return 0;
}