实验2 C语言表达式编程应用及输入输出函数

//ex1.cpp
#include<stdio.h>
int main(){
    int a=5, b=7, c=100, d, e, f;
    
    d = a/b*c;
    e = a*b/c;
    f = c/b*a;
    printf("d=%d, e=%d, f=%d\n",d,e,f);
    
    return 0;
} 

//ex2.cpp

#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("%lf\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;
}

//exp.cpp
#include <stdio.h>
int main() {
    double x,y;
    char c1,c2,c3;
    int a1,a2,a3;
    
    scanf("%d%d%d",&a1,&a2,&a3);
    printf("%d,%d,%d\n",a1,a2,a3);
    scanf("%c%c%c",&c1,&c2,&c3);
    printf("%c%c%c\n",c1,c2,c3);
    scanf("%lf,%lf",&x,&y);
    printf("%lf,%lf\n",x,y);
    
    return 0;
}

// ex4.cpp
#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')
        printf("%c是英文字母\n", x);
    else
        printf("%c是其它字符\n", x);
    
    
    return 0;
} 

// ex5.cpp
#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'||an1=='Y'&&ans2=='y'||ans2=='Y'")
        printf("\n罗马不是一天建成的:)\n");    
    else
        printf("\n罗马不是一天毁灭的。。。\n");

    return 0;
} 

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