作业二分支，循环结构

//计算和差积商余数
#include<stdio.h>
int main(void)
{
	int num1,num2;
	double y;
	char op;
	printf("type in an expression:");
	scanf("%d%c%d",&num1,&op,&num2);
	printf("%d%c%d",num1,op,num2);
   
	

	if(op=='+'){
		y=num1+num2;
	    printf("=%.2f\n",y);
	}
	else if(op=='-'){
		y=num1-num2;
	    printf("=%.2f\n",y);
	}
	else if(op=='*'){
		y=num1*num2;
	    printf("=%.2f\n",y);
	}
	else if(op=='/'){
		y=(num1/num2);
	    printf("=%.2f\n",y);
	}
	else if(op=='%'){
		y=num1%num2;
	    printf("=%.2f\n",y);
	}
	else{
		printf("unknown operator\n");
	}
	

	return 0;
}

　　

 

//不调用pow函数求幂
#include<stdio.h>
int main(void)
{
	int i,n;
	double x,y;
	printf("enter n:");
	scanf("%d",&n);
	printf("enter x:");
	scanf("%lf",&x);
	y=1;

	for(i=1;i<=n;i++){

		y=y*x;
	}

	printf("y=%.3f\n",y);

	return 0;
}
	

　　

 

//计算函数
#include<stdio.h>
int main(void)
{
	int m,n;
	double s,i;
	printf("m:");
	scanf("%d",&m);
	printf("n:");
	scanf("%d",&n);
	s=0;

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

	return 0;
}

　　

 

//计算数列
#include<stdio.h>
int main()
{
	int n,m;
	double s,i;
	printf("enter n:");
	scanf("%d",&n);
	s=0;
	m=1;
	for(i=1;i<=n;i++){
		s=s+m*(i/(2*i-1));
		m=(-1)*m;
	}
	printf("s=%.3f\n",s);

	return 0;
}

　　

 

//调用pow函数求幂
#include<stdio.h>
#include<math.h>
int main()
{
	int m,n,i;
	printf("enter n:");
	scanf("%d",&n);
	m=0;

	for(i=1;i<=n;i++){
		m=m+pow(2,i);
	}
	printf("m=%d\n",m);

	return 0;
}

　　

 

//计算贷款问题
#include<stdio.h>
#include<math.h>
int main()
{
	int year,money,loan;
	double rate,month,x,y;
	printf("enter loan:");
	scanf("%d",&loan);
	printf("enter rate:");
	scanf("%lf",&rate);

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

	return 0;
}