实验三

task1.c

源代码

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

void print_text(int line,int col,char text);
void print_spaces(int n);
void print_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);
    } 
    return 0;
} 
 
 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);
 }

结果

讨论：在0~24行，0~79列中随机选一行一列，在第line行打印（line-1）行空行，第col列打印（col-1）列空格，在第line行第col列输出“hi, April”，重复运行10次，每次间隔1000ms

task2-1.c

源代码

#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;
}

结果

添加后结果

task2-2.c

源代码

#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;
 }

结果

 task3.c

源代码

//task3.c
#include <stdio.h>
long long func(int n);   //函数声明

int main()
{
    int n;
    long long f;

    while (scanf_s("%d",&n) != EOF)
    {
        f = func(n); //函数声明
        printf("n = %d,f = %11d\n", n, f);
    }
    return 0;
}

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

结果

task4.c

源代码

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

int main()
{
    int n, m;

    while (scanf_s("%d%d", &n, &m) != EOF)
        printf("n = %d,m =%d,ans = %d\n", n,m, func(n, m));

    return 0;
}

//函数定义
int func(int n, int m)
{
    if (m == n || m == 0)
        return 1;
    else if (m > n)
        return 0;
    else
        return func(n - 1, m) + func(n - 1, m - 1);
}

结果

task5.c

源代码

#include<stdio.h>
#include<stdlib.h>
#include<math.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);
    }

    system("pause");
    return 0;

}

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

结果

task6.c

 源代码

#include <stdio.h> //好难理解，背下来吧
#include <stdlib.h>

void hanoi(int n,char from,char to,char temp);
int cishu(int n);


int main()
{
    char A,B,C;
    int n;
    while(scanf("%d",&n)!=EOF){
    hanoi(n,'A','C','B');
    printf("一共移动了%d步\n",cishu(n));
    
    system("pause");}
    return 0;

}
void hanoi(int n,char from,char to,char temp)
{
    if(n==1)
        printf ("%d:%c--->%c\n",n,from,to);
    else {
        hanoi(n-1,from,temp,to);
        
        printf ("%d:%c--->%c\n",n,from,to);
        hanoi(n-1,temp,to,from);
    }
}

int cishu(int n)
{
    if(n==1)
        return 1;
    if(n>1)
        return cishu(n-1)+1+cishu(n-1);
    if(n<1)
        return 0;
}

结果

task7.c

源代码

#include<stdio.h>
#include<stdlib.h>
#include<Windows.h>
int main(){
int a, b, i, j, count1, count2;
for (i = 2;i <= 20; i+=2)
{

    for (a = 2;a <= i/2; a++)
    {
        count1 = 0;
        for (j = 2;j <= a - 1;j++)
        {
              if (a% j==0)
              {
                  count1++;
                  break;
              }
        }
        if (count1 ==0)
        {
            count2 = 0;
            b=i-a;
            for (j= 2; j <= b- 1;j++)
            {
                if (b%j== 0)
                {
                    count2++;
                    break;
                }
            }
           if (count2 ==0)
           {
             printf("%d=%d+%d\n", i, a, b);
           }
        }
    }
}
system("pause");
             return 0;
                 }

结果

task8.c

源代码

#include <stdio.h>
#include<math.h>
long func(long s);
int main() {
    long s, t;
    printf("Enter a number:");
    while (scanf("%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 j, count = 0;
    long n=0;
    while (s != 0)
    {
        j = s % 10;
        s = s / 10;
        if (j % 2 != 0)
        {
            n += j * pow(10, count);
            count++;
        }
    }
    return n;

}

结果