实验4

#include <stdio.h>
long long fun(int n); 

int main() 
{
    int n;
    long long f;
    
    while(scanf("%d", &n) != EOF) 
    {
        f = fun(n); 
        printf("n = %d, f = %lld\n", n, f);
    }
    
    return 0;
}


long long fun(int n)
{
    long long result;

    if(n==1)
    result=1;
    else
    result=2*fun(n-1)+1;
    
    return result;
}

#include <stdio.h>
long long fac(int n);  // 函数声明 

int main() {
    int i,n;
    
    printf("Enter n: ");
    scanf("%d", &n);
    
    for(i=1; i<=n; ++i) 
        printf("%d! = %lld\n", i, fac(i)); 
    
    return 0;
}

// 函数定义 
long long fac(int n) {
    static long long p = 1;
    
    p = p*n;
    
    return p;
}

#include<stdio.h>
int func(int, int);

int main() {
    int k=4,m=1,p1,p2;
    
    p1 = func(k,m) ; 
    p2 = func(k,m) ;
    printf("%d,%d\n",p1,p2) ;
    
    return 0;    
}

int func(int a,int b) {   
    static int m=0,i=2;
    
    i += m+1;
    m = i+a+b;  
    
    return (m);
}

#include <stdio.h>
#include <stdlib.h> 
#define N 1000
int fun(int n,int m,int bb[N]) {
    int i,j,k=0,flag;
    
    for(j=n;j<=m;j++) {
          flag= 1;   
        for(i=2;i<j;i++)
            if(j%i==0) {  
                   flag=0;
                   break;
        }
        if(flag==1) 
           bb[k++]=j;
    }
    return k;
}

int main(){
    int n=0,m=0,i,k,bb[N];
    
    scanf("%d",&n);
    scanf("%d",&m);
    
    for(i=0;i<m-n;i++)
        bb[i]=0;
        
    k=fun(n,m,bb); 
    
    for(i=0;i<k;i++)
        printf("%4d",bb[i]);
        
    return 0;
}

#include <stdio.h>
void dec2n(int x, int n);  // 函数声明 

int main() {
    int x;
    
    printf("输入一个十进制整数: ");
    scanf("%d", &x);
    
    dec2n(x, 2);
    dec2n(x, 8); 
    dec2n(x, 16);
    
    return 0;
}

void dec2n(int x, int n) {
    int i, m;
    char a[100];
    for (i = 0;x != 0;i++) {
        a[i] = x%n;
        x = x / n;
    }
    if (a[i]>9)
        switch (a[i]){
        case 10:a[i] = ‘A‘;break;
        case 11:a[i] = ‘B‘;break;
        case 12:a[i] = ‘C‘;break;
        case 13:a[i] = ‘D‘;break;
        case 14:a[i] = ‘E‘;break;
        case 15:a[i] = ‘F‘;break;
        }
    for (m = i - 1;m >= 0;m--)
        printf("%X", a[m]);
    printf("\n");
}