实验三

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#include<windows.h>
#define N 80

void print_text(int line,int col,char text[]);//函数声明
void print_spaces(int n);//函数声明
void print_blank_lines(int n);//函数声明

int main(){
    int line,col,i;
    char text[N] = "hl,April~";
    
    srand(time(0));//以当前系统时间作为随机种子
    
    for(i = 1;i <=10;++i){
        line = rand()%25;
        col = rand()%80;
        print_text(line,col,text);
        sleep(1000);//暂停1000ms 
    } 
    return 0;
} 

//打印n个空格
void print_spaces(int n){
    int i;
    
    for(i = 1;i <= n;++i)
    printff("\n");
} 

//在第line 行第col列1打印一段文本
void print_text(int line,int col,char text[]){
    print_blank_lines(line-1);
    print_spaces(col-1);
    printf("%s",text);
} 

随机打印hi，April

#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! = %11d\n",i,fac(i));
    
    return 0;
}

long long fac(int n){
    static long long p=1;
    
    p=p*n;
    printf("p = %11d\n",p);    
    return p;
}

只赋值一次，之后每次调用函数时保留上次调用函数的值

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

int main(){
    int n;
    long long f;
    
    while (scanf("%d",&n) !=EOF){
        f = func(n);
        printf("n=%d,f=%11d\n",n,f);
        
    }
    
    return 0;
}

long long func(int n)
{
    long long int f;
    if(n==1)
    f=1;
    else
    f=2*func(n-1)+1;
    return f;
}

#include <stdio.h>
int func(int n, int m);
int ans=0;int main() {    
int n, m; while(scanf("%d%d", &n, &m) != EOF)        
printf("n = %d, m = %d, ans = %d\n", n, m, func(n, m));        return 0;
}
int func(int n, int m){        
if(n==m)        
ans=1;    
if(m==0)        
ans=1;    
if(n<m)        
ans=0;    
if(n>m)
{        
if( m !=0)            
ans = func(n-1,m)+func(n-1,m-1);        
else ans=1;    
} 
return ans;
}

#include <stdio.h>
double mypow(int x, int y); 
int main() 
{
    int x, y;
    double ans;
    while(scanf("%d%d", &x, &y) != EOF)
     {
        ans = mypow(x, y); 
        printf("%d的%d次方: %g\n\n", x, y, ans);
    }
    return 0;
}

double mypow(int x, int y)
{
    int i;
    double ans=1.0;
    if(y>=0)
    {
        for(i=1;i<=y;i++)
            ans=ans*x;
        return ans;

else
    {
        for(i=1;(i+y)<=0;i++)
            ans=ans/x;
        return ans;
    }
}

#include <stdio.h>
double mypow(int x, int y); 
int main() 
{
    int x, y;
    double ans;
    while(scanf("%d%d", &x, &y) != EOF)
     {
        ans = mypow(x, y); 
        printf("%d的%d次方: %g\n\n", x, y, ans);
    }
    return 0;
}

double mypow(int x, int y)
{
    double ans=1;
    if(y==0)
    ans=1;
    if(y>0)
        ans=ans*x*mypow(x,y-1);
    if(y<0)
        ans=ans/x*mypow(x,y+1);

return ans;
}

#include<stdio.h>
#include<stdlib.h>
void hanoi(unsigned int n,char from, char temp, char to);
void moveplate(unsigned int nth,char from,char to);
int main(){
    unsigned int n;
    while(scanf("%u",&n) !=EOF)
    hanoi(n,'A','B','C');
    return 0; 
    
} 

void hanoi(unsigned n,char from, char temp, char to){
    if(n==1){
    moveplate(n,from,to);
    }
    else
    {
        hanoi(n-1,from,to,temp);
        moveplate(n,from,to);
        hanoi(n-1,temp,from,to);

    }
    
}
void moveplate(unsigned nth,char from,char to){
    
    printf("%u:%c-->%c\n",nth,from,to);
}

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

int main(){
    int i,j,k;
    for(i=2;i<=10;i++){
        for(j=2;j<=i;j++){
             if(is_prime(2*i - j) == 1 && is_prime(j) == 1)
            {
                printf("%d = %d + %d\n", 2*i, j, 2*i - j);
                break;
        }
        
    }
}
}
int is_prime(int n)
{
    int i;
    
    for( i = 2; i < n; i++)
    {        
        if(n % i == 0)
            return 0;                        
    }
    
    return 1;
}

#include <stdio.h>
#include <stdlib.h>
#include <math.h>
long func(long s);

int main(){
    long s,t,i,m,n,k;

    printf("Enter a number:");
    while(scanf("%ld",&s)!=EOF){
        t=func(s);
        printf("new number is:%ld\n\n",t);
        printf("Enter a number:");
    }
    system("pause");
    return 0;
}

long func(long s){long i,n,k,m=0;
for(i=s,k=0;i>0;k++){
    n=i%10;
    i=i/10;
if ((n%2==0)||n==0)
    k--;
else
    m=m+n*(pow(10,k));}
return m;}