text 4

 1 #include<stdio.h>
 2 long long fun(int n);
 3 
 4 int main(){
 5     int n;
 6     long long f;
 7     
 8     while(scanf("%d", &n) != EOF){
 9         f = fun(n);
10         printf("n = %d, f = %lld\n", n, f);
11     }
12     
13     return 0;
14 }
15 
16 long long fun(int n){
17     if(n == 1)
18     return 1;
19     else
20     return 2*(fun(n-1)+1)-1;
21 }

#include<stdio.h>
long long fac(int n);
  
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;
}
 
long long fac(int n){
    static long long p = 1;
    
    p = p*n;
    
    return p;
}

#include<stdio.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];
    
    while(scanf("%d %d",&n, &m) != EOF){
    

    
    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]);
        printf("\n");
}
        
    return 0;
}

 1 #include <stdio.h>
 2 
 3 void dec2n(int x, int n); 
 4 
 5 int main() {
 6     int x;
 7     
 8     printf("输入一个十进制整数: ");
 9     scanf("%d", &x);
10     
11     dec2n(x, 2); 
12     dec2n(x, 8);
13     dec2n(x, 16);
14     return 0;
15 }
16  
17 void dec2n(int x, int n) {
18     int i,a,N;
19     if((n==2)||(n==8))
20     {    int b[100];
21         for(i=0;x!=0;i++){
22         
23         b[i] = x % n;
24         x =  x / n ;
25     }
26     printf("%2d进制：", n);
27     for(N=i-1;N>=0;N--)
28     printf("%d",b[N]);
29     printf("\n");    
30     }
31     
32     if(n==16)
33     {    char b[100];
34     
35         for(i=0;x!=0;i++)
36         {switch(x%n){
37             case 1:b[i]=‘1‘;break;
38             case 2:b[i]=‘2‘;break;
39             case 3:b[i]=‘3‘;break;
40             case 4:b[i]=‘4‘;break;
41             case 5:b[i]=‘5‘;break;
42             case 6:b[i]=‘6‘;break;
43             case 7:b[i]=‘7‘;break;
44             case 8:b[i]=‘8‘;break;
45             case 9:b[i]=‘9‘;break;
46             case 10:b[i]=‘A‘;break;
47             case 11:b[i]=‘B‘;break;
48             case 12:b[i]=‘C‘;break;
49             case 13:b[i]=‘D‘;break;
50             case 14:b[i]=‘E‘;break;
51             case 15:b[i]=‘F‘;break;
52         }
53         x = x / n;
54         }
55     printf("%d进制：", n);
56     for(N=i-1;N>=0;N--)
57     printf("%c" ,b[N]);
58     printf("\n");
59     }
60 }