实验3

task1.c

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

task2-1.c

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;
    
    printf("p=%lld\n",p); 

    p = p * n;

    return p;
}

结果

task2-2.c

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

代码

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

结果

task4.c

代码

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

结果

task5-1.c

代码

#include <stdio.h>
#include<stdlib.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)
{
    int i;
    double ans=1;
     for(i=1;i<=abs(y);i++)
           ans=x*ans;
    if(y==0)
        return 1;
    else if(y>0)
        return ans;
    else
        return 1.0/ans;
}

结果

task5-2.c

代码

#include <stdio.h>
#include<stdlib.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 x*mypow(x,y-1);
    else
        return 1/mypow(x,-y);
}

结果

task6.c

代码

#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 num;

int main() {
unsigned int n;
while(scanf("%u", &n) != EOF) {
    num = 0;
    hanoi(n, 'A', 'B', 'C');
    printf("一共移动了%d次\n", num);
}

    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);
   hanoi(n - 1, temp, from, to);
}
}

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

结果

task7.c

代码

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
int is_prime(int n);

int main(){
    int j,k;
    while(scanf("%d",&j)!=EOF){
        for(k=1;k<=j;k++)
            if(is_prime(k)&&is_prime(j-k))
                break;
        printf("%d=%d+%d\n",j,k,j-k);
    }
    system("pause");
    return 0;
}

int is_prime(int n){
    int i;
    double m;
    m=sqrt(1.0*n);
    for(i=2;i<=m;i++)
        if(n%i==0)break;
    if(n!=1&&i>m)
        return 1;
    else
        return 0;
}

结果

task8.c

代码

#include<stdio.h>
#include<math.h>
#include<stdlib.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: ");
}
   system("pause");
   return 0;
}
long func(long s){
long b=0,t=0;
    int a,m;
    while(s!=0){
        a=s%10;
        if(a%2!=0)
            b=10*b+a;
        s=s/10;
    }
    
    while(b!=0){
        m=b%10;
        t=10*t+m;
        b=b/10;
    }
    
    return t;
}

结果