C语言作业2

 

#include<stdio.h> 
int main(){
    int a=5, b=7, c=100, d, e, f;
    
    d=a/b*c;
    e=a*c/b;
    f=c/b*a;
    printf("d=%d,e=%d,f=%d/n",d,e,f);
    
    return 0;
}

#include<stdio.h>
int main(){
    int x=1234;
    float f=123.456;
    double m=123.456;
    char ch='a';
    char a[]="Hello,world!";
    int y=3,z=4;
    
    printf("%d%d\n",y,z);
    printf("y=%d,z=%d\n",y,z);
    printf("%8d,%2d\n",x,x);
    printf("%f,%8f,%8.1f,%0.2f,%.2e\n",f,f,f,f,f);
    printf("%1f\n",m);
    printf("%3c\n",ch);
    printf("%s\n%15s\n%10.5s\n%2.5s\n%.3s\n",a,a,a,a,a);
    
    return 0;
    
}

#include<stdio.h>
int main(){
    int x=1234;
    float f=123.456;
    double m=123.456;
    char ch='a';
    char a[]="Hello,world!";
    int y=3,z=4;
    
    printf("%d%d\n",y,z);
    printf("y=%d,z=%d\n",y,z);
    printf("%8d,%2d\n",x,x);
    printf("%f,%8f,%8.1f,%0.2f,%.2e\n",f,f,f,f,f);
    printf("%1f\n",m);
    printf("%3c\n",ch);
    printf("%s\n%15s\n%10.5s\n%2.5s\n%.3s\n",a,a,a,a,a);
    
    return 0;
    
}

#include<stdio.h>
int main(){
    char x;
    
    x=getchar();
    
    if(x>='0'&&x<='9') 
        printf("%c是数字字符\n",x);
    else if(x>='a'&&x<='z'||x>='A'&&x<='Z')
        printf("%c是英文字母\n",x);
    else
        printf("%c是其它字符\n",x);
        
    return 0;
}

#include<stdio.h>
int main(){
    char ans1,ans2;
    
    printf("复习了没？(输入y或Y表示复习了，输入n或N表示没复习):");
    ans1=getchar();
    
    getchar();
    printf("\n动手敲代码了没？(输入y或Y表示敲了，输入n或N表示木有敲):");
    ans2=getchar();
    
    if((ans1=='y'||ans1=='Y')&&(ans2=='y'||ans2=='Y'))
        printf("罗马不是一天建成的：）\n");
    else
        printf("罗马不是一天毁灭的。。。\n");
       
    return 0;
    
} 

#include<stdio.h>
#include<math.h>
int main(){
    int s,a1=1;
    double q=2,n;
    
    scanf("%lf",&n);
    s=a1*(1-pow(q,n))/(1-q);
    printf("n=%.0lf时,sum=%d",n,s);
    return 0;
    
}