实验3 函数应用编程

task1

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

void printf_text(int line,int col,char text[]);
void printf_spaces(int n);
void printf_blank_lines(int n);

int main()
{
    int line,col,i;
    char text[N]="hi,April~";
    
    srand(time(0));
    
    for(i=1;i<=10;i++)
    {
        line=rand()%25;
        col=rand()%80;
        print_text(line,col,text);
        Sleep(1000);
    }
}

void print_spaces(int n)
{
    int i;
    for(i=1;i<=n;i++)
    printf(" ");
}

void print_blank_lines(int n)
{
    int i;
    for(i=1;i<=n;i++)
    printf("\n");
}

void print_text(int line,int col,char text[])
{
    print_blank_lines(line-1);
    print_spaces(col-1);
    printf("%s",text);
}

功能：随机打印10个"hi,April", 每打印一个暂停1秒再换行

task2_1

#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;
    printf("%lld\n",p);
    p = p*n;
    return p;
}

task2_2

#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;
}

局部static变量的特性：保存上一次的数据直至下一次使用

task3

#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=%lld\n",n,f);
    }
    
    return 0;
}

long long func(int n)
{
    long long f;
    if(n==0)
        f=0;
    else
    f = 2*func(n-1)+1;
    
    return f;
}

task4

#include<stdio.h>
int func(int n,int m);
int fun(int n);
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 fun(int n)
{
    int i,p=1;
    for(i=1;i<=n;i++)
        p=p*i;
    return p;
}

int func(int n,int m)
{
    int ans;
    if(n<m)
        ans = 0;
    else if(m=n)
        ans = 1;
    else
        ans = fun(n-1)/fun(m)/fun(n-m-1) + fun(n-1)/fun(m-1)/fun(n-m-2);
    
    return ans;
}

task5_1

#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;
    else
        for(i=-1;i>=y;i--)
        ans = ans/x;
    return ans;
}

task5_2

#include<stdio.h>
double mypow(int x,int y);

int main()
{
    int x,y;
    double ans;
    
    while(scanf("%d%d",&x,&y))
    {
        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=1.0;
    if(y==0)
        ans = 1.0;
    else if(y>0)
        ans = x*mypow(x,y-1);
    else
        ans = 1/mypow(x,-y);
    
    return ans;
}

task6

#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);
long long func(int n);
int main()
{
    unsigned int n;
    while(scanf("%u",&n) !=EOF)
    {
    hanoi(n,'A','B','C');
    printf("一共移动了%lld次\n\n",func(n));
    }
    return 0;
}

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

long long func(int n)
{
    long long f;
    if(n==0)
        f=0;
    else
    f = 2*func(n-1)+1;
    
    return f;
}

task7

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
int is_prime(int n);
int main()
{
    int i,j;
    
    for(j=4;j<=20;j+=2)
    {
        for(i=2;i<=j/2;i++)
        {
            if(is_prime(i)&&is_prime(j-i))
            {
                printf("%d=%d+%d\n",j,i,j-i);
                break;
            }
        }
    }
    return 0;
}

int is_prime(int n)
{
    int i,flag;
    for(i=2;i<=sqrt(1.0*n);i++)
    {
        if(n%i==0)
            {
            return 0;
            break;
            }
    }
    if(n>1&&i>sqrt(1.0*n))
        return 1;
    else 
    return 0;
}

task8

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

int main() 
{
    long s, t;
    printf("Enter a number: ");
    while (scanf_s("%ld", &s) != EOF) 
    {
        t = func(s); 
        printf("new number is: %ld\n\n", t);
        printf("Enter a number: ");
    }
    return 0;
}
long func(long s) 
{
    int t, n=0, i = 0;
    while (s != 0)
    {
        t = s % 10;
        if (t % 2 ==1)
        {
            n = n+t*pow(10, i);
            i++;
        }
        s= s/ 10;
    }
    return n;
}