1.#include<stdio.h>//三角形int main(){        printf("*\n");    printf("**\n");    printf("***\n");    printf("****\n");    printf("*****\n");    printf("******\n");    printf("*******\n");    printf("********\n");    printf("*********\n");    printf("**********\n");
    return 0；    }

2.#include<stdio.h>//矩形 int main(){    printf("**********\n");    printf("**********\n");    printf("**********\n");    printf("**********\n");    printf("**********\n");    printf("**********\n");    printf("**********\n");    printf("**********\n");    printf("**********\n");    printf("**********\n");    return 0；}

3.#include<stdio.h>//倒三角形 int main(){    printf("**********\n");    printf("*********\n");    printf("********\n");    printf("*******\n");    printf("******\n");    printf("*****\n");    printf("****\n");    printf("***\n");    printf("**\n");    printf("*\n");
    return 0；}

4.#include<stdio.h> // 成绩 int main(){    char score;    scanf("%c",&score);    switch (score)    {        case ‘A‘:              printf("90~100");              break;        case ‘B‘:              printf("80~89");              break;         case ‘C‘:              printf("70~79");              break;        case ‘D‘:              printf("60~69");              break;        case ‘E‘:              printf("0~59");              break;     } 
        return 0；  }

5.#include<stdio.h> //温度的转换 int main(){    int F=100;//F为华氏温度，C为摄氏温度     int C;    C=(5*(F-32)/9);     printf("%d",C);    return 0;}

6.#include<stdio.h>//下落距离 int main(){    int t=3;    int g=10;    int H;//下落高度     H=0.5*g*t*t;    printf("f(t)=%d",H);    return 0;    }

7.#include<stdio.h>int main(){   int a,b,c,x;    x=152;    a=x%10;    b=(x/10)%10;    c=x/100;   printf（）   }

8.#include<stdio.h>#include<math.h>int main()//函数 {    double x;    double y;    scanf("%lf",&x);    if(x>=0)           y=sqrt(x);    else           y=pow(x+1,2)+2*x+1/x;printf("f(x)=%f",y);return 0;           }

#include<stdio.h> 电费#include<math.h>int main(){    double x;    double cost;    printf("请输入x的值");    scanf("%lf",&x);    if(x>0&&x<=50)       printf("cost=%f",cost=0.53*x);    else if(x>50)       printf("cost=%f",cost= 50*0.53+(x-50)*0.58);    else       printf("Invalid Value!"); }