实验三

task1.c#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);
}

功能：在任意一行一列打印"hi November",共进行十次。

task2.1c

#define _CRT_SECURE_NO_WARNINGS

#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;
}

task2.2c

//

#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;
}

实验任务3

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

实验任务4

#define _CRT_SECURE_NO_WARNINGS
#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;
    if (m > n)
        return 0;
    return func(n - 1, m) + func(n - 1, m - 1);

}

实验任务5

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
int mul(int n, int m);
int main() {
    int n, m;
    while (scanf("%d%d", &n, &m) != EOF)
        printf("%d*%d=%d\n", n, m, mul(n, m));

    return 0;
}
int mul(int n, int m) {
    int i,s=0;
    for (i = 1; i <= m; ++ i)
        s += n;
    return s;
}

实验任务6

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<stdlib.h>
#include<math.h>
void hanoi(unsigned int n, char from, char temp, char to);
void moveplate(unsigned int n, char from, char to);
int main() {
    unsigned int n,m;
    while (scanf("%u", &n) != EOF) {
        hanoi(n, 'A', 'B', 'C');
        m = pow(2, n) - 1;
        printf("\n");
        printf("一共移动了%d次\n", m);
    }
    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) {
    printf("%u:%c-->%c\n",n,from,to);
}

task6.c

实验任务7

#include<stdio.h>
#include<stdlib.h>
int is_prime(int n);
int main()
{
    int i,n;
    for (i = 4; i <= 20; i=i+2) 
        for (n = 2; n <= i / 2; n++) 
            if (is_prime(n) && is_prime(i - n)) {
                printf("%d=%d+%d\n", i, n, i - n);
                break;
            }

    system("pause");
    return 0;
}
int is_prime(int n) {
    int i;
    for (i = 2; i <= n / 2; i++) {
        if (n % i == 0)
            break;
    }
    if (i > n / 2 && n > 1)
        return 1;
    else
        return 0;
}

实验任务8

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<math.h>
long fun(long s);
int main()
{
    long s, t;

        printf("Enter your answer:");
        while (scanf("%ld", &s) != EOF) {
            t = fun(s);
            printf("new number is :%ld\n\n", t);
            printf("Enter your answer:");
        }
    return 0;
}
int fun(long s) {
    int a=0, i = 0;
    while(s>0) {
        if (s % 2 == 0)
            s = s / 10;
        else {
            i += pow(10, a) * (s % 10);
            s = s / 10;
            a++;
        }
    }
    return i;
}