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

#include<stdio.h>#include<math.h>int main() {    float x,y;    printf("请输入一个数x:\n");    scanf("%f",&x);    if(x>4)        y=sqrt(x-4);    else if(x<-5)        y=fabs(x);    else        y=x+3;    printf("x=%fy=%.2f\n",x,y);    return 0;     }

#include<stdio.h>int main(){    char c;    printf("请输入一个小写字母:");     scanf("%c",&c);    printf("%c",c-32);    return 0;}

#include<stdio.h>int main(){     float x,y;    printf("请输入一个整数x：\n");        scanf("%1f",&x);    if(x<1)        y=x;    else if(x>=10)        y=3*x-11;    else        y=2*x-1;    printf("x=%fy=%.2f",x,y);    return 0;}

#include<stdio.h>int main(){    int a;    char c;    printf("请输入成绩：\n");    scanf("%f%c",&a,&c);    switch (a)    {    case 9:        printf("A\n");break;        case 8:        printf("B\n");break;       case 7:           printf("C\n");break;    case 6:        printf("D\n");break;    default:        printf("E\n");break;}            return 0;}

#include<stdio.h>int main(){     int a;            printf("请输入学生成绩：");      scanf("%d",&a);     if(a>=90)         printf("学生成绩等级为A:");      else if(a>=80 && a<=89)         printf("学生成绩等级为B:");     else if(a>=70 && a<=79)         printf("学生成绩等级为C:");         else if(a<60)          printf("学生成绩等级为E:");     else         printf("学生成绩等级为D:");      return 0;}