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, November~";
    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);
}

Task2

#include <stdio.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! = %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;
}

#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;
}

Task3

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

int main() {
    int n;
    long long f;

    while (scanf_s("%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;
}

 Task4

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

}

Task5

 

#include <stdio.h>

int mul(int n, int m);

int main() {
    int n, m;

    while (scanf_s("%d%d", &n, &m) != EOF)
        printf("%d * %d = %d\n", n, m, mul(n, m));

    return 0;
}
int mul(int n, int m) {
    if (n == 1)
        return m;
    if (m == 1)
        return n;
    if (n == 0 || m == 0)
        return 0;
    else return n+mul(n, m - 1);

}

Task6

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

void hanoi(int n, char from, char temp, char to);
void moveplate(int n, char from, char to);
int count = 0;
int main()
{
    unsigned int n;
    while (scanf_s("%u", &n) != EOF)
    {
        hanoi(n, 'A', 'B', 'C');
        printf("\n一共移动了%d次\n",count);
        count = 0;
    }
    return 0;
}
void hanoi(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(int n, char from, char to)
{
    printf("%u:%c --> %c\n", n, from, to);
    count++;
}

Task7

#include<stdio.h>
#include<math.h>
int prime(int n);
int main() {
    int k=2;
    while (k<20) {
        k += 2;
        for (int i = 2; i <= k / 2; i++) {
            if (prime(i) && prime(k - i))
                printf("%d=%d+%d\n", k, i, k - i);
        }
    }
    return 0;
}
int prime(int n) {
    int j;
    if (n == 1)
        return 0;
    for (j = 2; j <=sqrt(n); j++) {
        if (n % j == 0)
            return 0;
    }
    return 1;
}

Task8

#include<stdio.h>
#include<math.h>
long fun(long s);

int main() {
    long s, t;

    printf("Enter a number: ");
    while (scanf_s("%ld", &s) != EOF)
    {
        t = fun(s);
        printf("new number is: %ld\n\n", t);
        printf("Enter a number: ");
    }

    return 0;
}
long fun(long s)
{
    int n;
    double num = 0;
    int count = 0;
    while (s != 0)
    {
        n = s % 10;
        if (n % 2 != 0)
        {
            num = pow(10, count) * n + num;
            count++;
        }
        s /= 10;
    }
    return num;
}