第四次作业

1.编写程序，判断一个数n是正数还是负数

#include<stdio.h>
main(){
	int n;
	scanf("%d",&n);

	if(n>0){
		printf("%d是正数\n",n);}
	else{printf("%d是负数\n",n);}

}

　　

 

 

 

 2.编写程序，计算出出租车的行驶距离与费用之间的关系，起步3km内，8元；之后1.6元/km

#include<stdio.h>
main(){
/*	int n;
	scanf("%d",&n);

	if(n>0){
		printf("%d是正数\n",n);}
	else{printf("%d是负数\n",n);}

}*/
	double x,feiyong;
	printf("请输入行驶距离:\n");
	scanf("%lf",&x);
	feiyong=8+1.6*(x-3);
	if(x<3){
		printf("费用是8",feiyong);}
	else{
		printf("费用是%lf\n",feiyong);}
}

　　

 

 3.输入一个数，判断是奇数还是偶数

#include<stdio.h>
main(){
/*	int n;
	scanf("%d",&n);

	if(n>0){
		printf("%d是正数\n",n);}
	else{printf("%d是负数\n",n);}

}
	double x,feiyong;
	printf("请输入行驶距离:\n");
	scanf("%lf",&x);
	feiyong=8+1.6*(x-3);
	if(x<3){
		printf("费用是8",feiyong);}
	else{
		printf("费用是%lf\n",feiyong);}
}*/
	int x;
	scanf("%d",&x);
	if(x%2==0){
		printf("是偶数");}
	else{printf("是奇数");}
}

　　

 

 

 

 4.输入一个数，输出它的绝对值

#include<stdio.h>
main(){
/*	int n;
	scanf("%d",&n);

	if(n>0){
		printf("%d是正数\n",n);}
	else{printf("%d是负数\n",n);}

}
	double x,feiyong;
	printf("请输入行驶距离:\n");
	scanf("%lf",&x);
	feiyong=8+1.6*(x-3);
	if(x<3){
		printf("费用是8",feiyong);}
	else{
		printf("费用是%lf\n",feiyong);}
}
	int x;
	scanf("%d",&x);
	if(x%2==0){
		printf("是偶数");}
	else{printf("是奇数");}
}*/
	int x;
	scanf("%d",&x);
	if(x>0){
		printf("%d\n",x);}
		else{printf("绝对值是%d\n",x*-1);}
}

　　

 

 

 

 5.输入2个数，输出较大的数

#include<stdio.h>
main(){
/*	int n;
	scanf("%d",&n);

	if(n>0){
		printf("%d是正数\n",n);}
	else{printf("%d是负数\n",n);}

}
	double x,feiyong;
	printf("请输入行驶距离:\n");
	scanf("%lf",&x);
	feiyong=8+1.6*(x-3);
	if(x<3){
		printf("费用是8",feiyong);}
	else{
		printf("费用是%lf\n",feiyong);}
}
	int x;
	scanf("%d",&x);
	if(x%2==0){
		printf("是偶数");}
	else{printf("是奇数");}
}
	int x;
	scanf("%d",&x);
	if(x>0){
		printf("绝对值是%d\n",x);}
		else{printf("绝对值是%d\n",x*-1);}
}*/
	int x,y;
	scanf("%d%d",&x,&y);
	if(x>y){
		printf("较大数是%d",x);}
	else{printf("较大数是%d",y);}
}

　　

 

 6.输入一个字符，如果是大写就转成小写，如果是小写就转成大写并输出

#include<stdio.h>
main(){
/*	int n;
	scanf("%d",&n);

	if(n>0){
		printf("%d是正数\n",n);}
	else{printf("%d是负数\n",n);}

}
	double x,feiyong;
	printf("请输入行驶距离:\n");
	scanf("%lf",&x);
	feiyong=8+1.6*(x-3);
	if(x<3){
		printf("费用是8",feiyong);}
	else{
		printf("费用是%lf\n",feiyong);}
}
	int x;
	scanf("%d",&x);
	if(x%2==0){
		printf("是偶数");}
	else{printf("是奇数");}
}
	int x;
	scanf("%d",&x);
	if(x>0){
		printf("绝对值是%d\n",x);}
		else{printf("绝对值是%d\n",x*-1);}
}
	int x,y;
	scanf("%d%d",&x,&y);
	if(x>y){
		printf("较大数是%d",x);}
	else{printf("较大数是%d",y);}
}*/
	char a,b;
	printf("请输入一个字符");
	scanf("%c",&a);
	if(a<=90){
        b=a+32;
    }else{
        b=a-32;
    }
    printf("%c",b);
}