实验四

#include <stdio.h>
long long fun(int n);  
int main() {
    int n;
    long long f;
    
    while(scanf("%d", &n) != EOF) {
        f = fun(n);  // 函数调用 
        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)-1;
    return result;
} 

#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=j;   
        for(i=2;i<j;i++)
            if(flag%i==0)
            {  
                flag=0;
                break;
            }
        if(flag!=0) 
            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;
}

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,a,N;
    char b[100];

    for(i=0;x!=0;i++){
    b[i] = x % n;
    x =  x / n ;
    }
    if(b[i]>9)
    switch(b[i])
    {
        case 10:b[i]='A';break;
        case 11:b[i]='B';break;
        case 12:b[i]='C';break;
        case 13:b[i]='D';break;
        case 14:b[i]='E';break;
        case 15:b[i]='F';break;
    }

    printf("%2d 进制：", n); 
    for(N=i-1;N>=0;N--)
    printf("%X" ,b[N]);
    printf("\n");

}