实验三

task1

源代码

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

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

}

运行结果

task2_1

源代码

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

int main() {
    int i, n;

    printf("ENTER n:");
    scanf_s("%d", &n);
    for (i = 1; i <= n; ++i)
        printf("%d!=%11d\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;
}

运行结果

task2_2

源代码

#include <stdio.h>
#include <stdlib.h>
int func(int a, int b);

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;//3 //12
    m = i + a + b;//8//17
    return m;
}

运行结果

task3

源代码

#include <stdio.h>
long long func(int n); // 函数声明
int main() {
    int n;
    long long f;
    while (scanf_s("%d", &n) != EOF) {
        f = func(n); // 函数调用
        printf("n = %d, f = %lld\n", n, f);
    }
    return 0;
}
long long func(int n) {
     static long long ans;
     if (n == 1)
         return 1;
     else {
         ans = ((func(n - 1) + 1) * 2) - 1;
         return  ans;
     }
}

实验结果

task4

 源代码

#include <stdio.h>
int func(int n, int m);
int main() {
    int n, m;
    while (scanf_s("%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 ans;
    if (n < m)
        return 0;
    else if (n == m || m == 0)
        return 1;
    else {
        return  func(n - 1, m - 1) + func(n-1, m );
        
    }


}

运行结果

task5

源代码

#include <stdio.h>
double mypow(int x, int y);


int main() {
    int x, y;
    double ans;
    while (scanf_s("%d%d", &x, &y) != EOF) {
        if (y > 0)
            ans = mypow(x, y);
        else {
            y = -y;
            ans = 1.0 / mypow(x, y);
        }
        printf("%d的%d次方: %g\n\n", x, y, ans);
    }
    return 0;
}
double mypow(int x, int y) {
    if (y == 1)
        return x;
    else
        return mypow(x, y - 1) * x;
}

实验结果

task6

源代码

#include<stdio.h>

int hannoi_step(int n);
void hannoi_move(int n, char A, char B, char C);

int hannoi_step(int n) {

    if (n <= 1)
        return 1;
    else
        return 2 * hannoi_step(n - 1)+1;
}
void hannoi_move( int n,char from, char temp, char to) {
    if (n == 1)
        printf("%d:%c-->%c\n",n, from, to);
    else
    {
        hannoi_move(n - 1, from, to,temp);
        printf("%d:%c-->%c\n",n, from, to);
        hannoi_move(n - 1, temp, from, to);
    }

}
int main()
{
    int n=0, ans;
    
    while (scanf_s("%d", &n) != EOF) {
        ans = hannoi_step(n);

        printf("一共移动了%d次\n", ans);
        hannoi_move(n, 'A', 'B', 'C');
    }
    
    return 0;
}

运行结果

task7

源代码

#include<stdio.h>


int is_prime(int n);

int is_prime(int n) {
    if (n <= 1)
        return 0;
    else {
        for (int i = 2; i < n; ++i) {
            if (n % i == 0)
                return 0;
        }
        return 1;
    }
}

int main()
{
    int ans, num,i;
    
    for (int m = 1; m <101; ++m) {
        if (m % 2 == 0) {
            num = m;
            for (i = 2; i <=num / 2; ++i) {

                if (is_prime(i) && is_prime(num - i)) {
                    printf("%d=%d+%d\n", num, i, num - i);
                    break;
                }
            }
        }
        else
            continue;
    }
    
    return 0;
}

运行结果

task8

源代码

#include <stdio.h>
#include <math.h>
long func(long s);
int main() {
    long s, t;
    printf("Enter a number: ");
    while (scanf_s("%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  ans, m, t;
    m =t= 0;
    while(s>0) {
        
        ans = s % 10;
        if (ans % 2)
            m = m * 10 + ans;
        else
            m = m;
        s = s / 10;
    }
    while (m > 0) {
        t = t * 10 + m % 10;
        m = m / 10;
    }
    return t;
}

运行结果