C语言实验3

实验任务3-1

 

#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_black_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_black_lines(int n){
    int i;
    
    for(i=1;i <= n;++i)
        printf("\n");
}

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

 

 

实验任务3-2-1

#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;

    p = p * n;

    return p;
}

 

实验任务3-2-2

// 练习：局部static变量特性

#include <stdio.h>
int func(int, int);        // 函数声明

int main() {
    int k = 4, m = 1, p1, p2;

    p1 = func(k, m);    // 函数调用
    p2 = func(k, m);    // 函数调用
    printf("%d, %d\n", p1, p2);

    return 0;
}

// 函数定义
int func(int a, int b) {
    static int m = 0, i = 2;

    i += m + 1;
    m = i + a + b;

    return m;
}

当函数返回后，局部静态变量static的值不会被销毁，而是保留下来，在下次调用函数时，这个变量的值还是上一次离开时的值。这不同于普通的局部变量，它们会在函数返回后被销毁。

 

实验任务3

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

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

    while (scanf("%d", &n) != EOF) {
        f = func(n); // 函数调用
        printf("n = %d, f = %lld\n", n, f);
    }

    return 0;
}

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

 

 

实验任务3-4

 

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

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;
}

// 函数定义
int func(int n, int m){
    int i;
    int up=1;
    int down=1;
    
    if(m>n)
    {
        return 0;
    }
    else if(m==0&&n==0)
    {
        return 1;
    }
    
    else
    {
    for(i=1;i<=m;i++)
    {
        up*=n-i+1;
        down*=i;
    }
    return up/down;

 

实验任务3-5

#include<stdio.h>
#include<stdlib.h>
#include<math.h>

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

int main()
{
    unsigned int n;
    int s;
    while(scanf("%d",&n)!=EOF)
    {
    hanoi(n,'A','B','C');
    s=pow(2,n)-1;
    printf("一共移动了%d次\n",s); 
}
    system("pause");
    return 0;
 } 
 
 void hanoi(unsigned int n,char from,char temp,char to)
 {
     if(n==1)
      moves(n,from,to);
     else
     {
         hanoi(n-1,from,to,temp);
         moves(n,from,to);
         hanoi(n-1,temp,from,to);
     }
 }
 
 void moves(unsigned int n,char from,char to)
 {
     printf("%d:%c-->%c\n",n,from,to);
 }

 

 

实验任务3-6

#include <stdio.h>
#include <math.h>
long func(long s);   // 函数声明

int main() {

    long s, t;

    printf("Enter a number: ");
    while (scanf("%ld", &s) != EOF) {
        t = func(s); // 函数调用
        printf("new number is: %ld\n\n", t);
        printf("Enter a number: ");
    }

    return 0;
}

// 函数定义
// 待补足。。。

long func(long s){
    long ans;
    long digit,t;
    
    ans=0;
    t=1;
    
    while(s!=0){
        digit=s%10;
        
        if(digit%2){
            ans +=t*digit;
            t*=10;
        }
        s /=10;
    }
    return ans;
}