实验三

task.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_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);
}

在十秒内每秒在一个随机位置生成“hi，April~"

task 2

1.原

#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;
}

1.添加后

#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("p=5%d\n",p);
    
    p=p*n;
    
    
    return p;
}

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;
}

一致

static变量可以修饰局部变量使其被调用时只被初始化一次，之后的计算在上一次运算得到的结果上继续进行。

task.3

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

task.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;
}
int func(int a,int b){
    int result;
    if(a<b)
    return 0;
    if(a==b||b==0)
    return 1;
    if(b==1)
    return a;
    else
    result=func(a-1,b)+func(a-1,b-1);
    return result;
    
}

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 a,int b){
    double ans=1.0;
    int i;
if(b>=0){
    for(i=1;i<=b;i++){
        ans=ans*a;
    }
    return ans;    
}
else{
        for(i=-1;i>=b;i--){
        ans=ans/a;
    }
    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)!=EOF){
        ans=mypow(x,y);
        printf("%d的%d次方：%g\n\n",x,y,ans);
    }
    return 0;
}

double mypow(int a,int b){
    double ans;if(b==0)
    return 1;
    else if(b>0){
    ans=a*mypow(a,b-1);
    return ans;        
    }
    else{
    ans=(1.0/a)*mypow(a,b+1);
    return ans;            
    }

    
}

task.6

#include<stdio.h>
#include<stdlib.h>
void hanoi(unsigned int n,char from,char temp,char to);
void moveplate(unsigned int n,char from,char to);
int flag=0;
int main()
{
    unsigned int n;
    while(scanf("%u",&n)!=EOF){
    hanoi(n,'A','B','C');
    printf("\n");
    printf("一共移动了%d次\n",flag);
    printf("\n");}    
    system("pause");
    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);
        flag++;
        hanoi(n-1,from,to,temp);    
    }

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

}

task.7

#include<stdio.h>
int is_prime(int n);
int main(){
    int a,n=2,m,flag1=0,flag2=1;
    while(scanf("%d",&a)!=EOF){
    while(flag1!=1||flag2!=1)
    {
    m=a-n;
    if(m==2&&flag2==1)
    break;
    else{
    flag1=is_prime(m);
    flag2=is_prime(n);    
    n++;
    }
    }
    flag2=is_prime(n);    
    if(flag2==0)
    n--;
    printf("%d=%d+%d\n",a,n,m);    
    }

    return 0;
}

int is_prime(int n){
    int t,flag=1;
    for(t=2;t<n-1;t++){
        if(n%t==0)
        flag=0;
        break;
    }
    return flag;
}

task.8

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