实验三

TASK1

#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);
}

功能：每隔一秒随机打印一个“hi，april”，位置由函数决定。
TASK2.1.1

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

int main() {
    int i, n;

    printf("Enter n: ");
    scanf("%d", &n);

    for (i = 1; i <= n; ++i)
        printf("%d! = %lld\n", i, fac(i));
    system("pause");
    return 0;
}

// 函数定义
long long fac(int n) {
    static long long p = 1;
    
    p = p * n;

    return p;
}

TASK2.1.2

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

int main() {
    int i, n;

    printf("Enter n: ");
    scanf("%d", &n);

    for (i = 1; i <= n; ++i)
        printf("%d! = %lld\n", i, fac(i));
    system("pause");
    return 0;
}

// 函数定义
long long fac(int n) {
    static long long p = 1;
    printf("p = %lld\n", p);
    p = p * n;

    return p;
}

TASK2.2

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

int main() {
    int i, n;

    printf("Enter n: ");
    scanf("%d", &n);

    for (i = 1; i <= n; ++i)
        printf("%d! = %lld\n", i, fac(i));
    system("pause");
    return 0;
}

// 函数定义
long long fac(int n) {
    static long long p = 1;
    printf("p = %lld\n", p);
    p = p * n;

    return p;
}

TASK3

#include <stdio.h>
#include<stdlib.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);
    }
    system("pause");
    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;
}

TASK4
迭代法：

#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;
}
int func(int n, int m){
	int s,a=1,b=1,c=1,d;
	if(m==0){
		s=1;
	}
	else if(m>n){
		s=0;
	}
	else{
		for(d=n-m;n>0;){
			a=a*n--;
			if(m>0)
			b=b*m--;
			if(d>0)
			c=c*d;
		}
		s=a/(b*c);
	}
	return s;
}

递归法：

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

    system("pause");
    return 0;
}
int func(int n,int m)
{
    int ans;

    if(n<m)
       ans=0;
    else if(m==n)
         ans=1;
      else if(m==1)
        ans=n;
    else if(m==0)
        ans=1;
      else
        ans=func(n-1,m)+func(n-1,m-1);

    return ans;
}

TASK5

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
void plate(char from,char to,char temp ,unsigned int n,int *p);
void trans(char from,char to,unsigned int n,int *p);
int main()
{
    unsigned int n;
    while(scanf("%d",&n)!=EOF)
        {
            int s=0;
            plate('A','C','B',n,&s);
            printf("\n一共移动了%d次\n\n",s);
        }
    system("pause");
    return 0;
}
void plate(char from,char to,char temp ,unsigned int n,int *p)
{
    if(n==1)
            trans(from,to,n,p);
    else
        {
            plate(from,temp,to,n-1,p);
            trans(from,to,n,p);
            plate(temp,to,from,n-1,p);
    }

}
void trans(char from,char to,unsigned int n,int *p)
{
    printf("%d: %c --> %c\n",n,from,to);
     *p=*p+1;
}

TASK6

#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 i=0,n,m=1;
	while(s){
		n=s%10;
		if(n%2!=0){
			i=i+n*m;	
			m=m*10;
		}
		s=s/10;
	}
	return i;
}