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_black_line(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); 
}

 

使“hi，April”随机出现在屏幕上，每个“hi，April”间间隔随机间隔line-1行及col-1空格

task2-2

#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;
}

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;
}

static使得执行main函数时变量不再被初始化，变量数值得以保留

task3

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

int main(){
    int n;
    long long f;
    printf("请输入一个0~32之间的整数\n");
    while(scanf("%d",&n)!=EOF){
        f=func(n);
        printf("n=%d,f=%lld\n",n,f);     
    } 
    
    return 0;
} 

long long func(int n){
    int f;   
    for(int i=1;i<=n;i++){
        f=2*f+1;
    }
    return f;
}

task4

#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){
if (n==m || m==0){return 1;}
else if(n<m){return 0;}
else
return func(n-1,m)+func(n-1,m-1);

}

task5

#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){
    double ans=1;
    if(y>=0){
        for(int i=1;i<=y;i++){
            ans=ans*x;
        }
    }
    if(y<0){
        for(int i=1;i<=-y;i++){
            ans=ans/x;
        }
    }
    return ans;
}

task6

#include<stdio.h>

void move(char getone,char putone){
    printf("%c--->%c\n",getone,putone);
}
void hanoi(int n,char one,char two,char three){
    if(n==1) move(one,three);
    else{
        hanoi(n-1,one,three,two);
        move(one,three);
        hanoi(n-1,two,one,three);
    }
}
int main(){
    int m,n=1,sum;
    while(scanf("%d",&m)!=EOF){
    hanoi(m,'A','B','C');
    for(int i=1;i<=m;i++){
        n=2*n;
        sum=n-1; 
        if(i==m)n=1;
    }
    printf("一共移动了%d次\n",sum);
    
    }return 0;

task7

#include<stdio.h>
#include<stdlib.h>
#include<math.h>
int is_prime(int n);
int main()
{
    int n,p,q,a,b;
    for(n=4;n<=20;n+=2)
    {p=1;
    do{
        p++;
        q=n-p;
        a=is_prime(p);
        b=is_prime(q);
    }
    while(a*b==0);
    printf("%d=%d+%d\n",n,p,q);
    }
    return 0;
    }
    int is_prime(int n){
        int k;
        for(k=2;k<=sqrt(n);k++)
        if(n%k==0)
        {
            return 0;
        }
    
    return 1;
}

task8

#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){
    long g=0,l=0;int t;
    while(s!=0){
        t=s %10;
        s=s/10;
        if(t%2!=0){
            l=l*10+t;
        }
    }
    while(l!=0){
        t=l%10;
        l=l/10;
        g=g*10+t;
    }
    return g;
}