作业2. 牛凯160809211

#include <stdio.h>
  int main(){
      int a,b,c,t;
      printf("请输入三个整数：");
      scanf("%d%d%d",&a,&b,&c);
      if(a<b){  
          t = a;
          a = b; 
          b = t;
     }
     if(b>c){
         printf("%d\t%d\t%d\n",a,b,c);
     } 
     else if(c>a){
         printf("%d\t%d\t%d\n",c,a,b);
     }
     else{
         printf("%d\t%d\t%d\n",a,c,b);
     } 
	 return 0; 
 }

#include <stdio.h>
#include <math.h>
 int  main(){
    int x,y;
    printf ("请输入x值：");
        scanf("%d",&x);
    if(x>4){
        y=sqrt(x-4);
        printf("%d\n",y);
    }
    else if(x<-5){
        y=fabs(x);
        printf("%d\n",y);
    }
    else{
        y=x+3;
        printf("%d\n",y);
    }
	return 0;
}

#include <stdio.h>
int main(){
	char c;
	printf("请输入字符：\n");
	scanf("%c",&c);
	printf("大写字符为：%c\n",c-32);

}

#include <stdio.h>
#include <math.h>
int main(){
    int x,y;
    printf("输入X：");
    scanf("%d",&x);
    if(x<1){
        y=x;
        printf("%d\n",y);
    }
    else if(1<=x && x<10){
        y=(2*x-1);
        printf("%d\n",y);
    }
    else{
        y=(3*x-11);
        printf("%d\n",y);
    }
	return 0;
}

#include <stdio.h>
int main(){
    int x;
    printf ("输入成绩：");
    scanf("%d",&x);
    if(x>=90)
        printf("A");
    else if(x>=80 && x<=89)
        printf("B");
    else if(x>=70 && x<=79)
        printf("C");
    else if(x>=60 && x<=69)
        printf("D");
    else
        printf("E");
}