作业3

1.任务1

#include<stdio.h>
#include<stdlib.h>
#include<time.h>
#include<windows.h>
#define N 80
void print_text(int line, int col, char test[]);
void print_spaces(int n);
void print_blank_lines(int n);
int main()
{
    int line, col, i;
    char text[] = "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 test[]) {
    print_blank_lines(line-1);
    print_spaces(col - 1);
    printf("%s", test);

}

在随机位置打出字符

2.实验任务2

#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;
        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", 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;
}

3. 实验任务3

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

4. 实验任务4

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

5. 实验任务5

#include<stdio.h>
int mul(int n, int m);
int main()
{
    int m, n;
    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 < m) {
        int t;
        t = m;
        m = n;
        n = t;
    }
    if (m == 0) {
        return 0;
    }
    else { return mul(n, m - 1) + n; }
}

6. 实验任务6

#include<stdio.h>
#include<stdlib.h>
int count = 0;
void Hanoi(int n, char from, char temp, char to);
void moveplate(int n, char from, char to);
int main()
{
    int n;
    while (scanf_s(" %d", &n) != EOF) {
        count = 0;
        Hanoi(n, 'A', 'B', 'C');
        printf("\n一共移动了%d次\n", count);
    }
    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("%d:%c-->%c\n", n, from, to);
    count++;
}

7. 实验任务7

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
int is_prime(int n);
int main()
{
    int n,i;
    while (scanf_s("%d",&n) != EOF) {
        for (i = 2; i <= n/2; i++) {
            int flag_1 = 0, flag_2 = 0;
            if (is_prime(i)) { flag_1 = 1; }
            if (is_prime(n - i)) { flag_2 = 1; }
            if (flag_1 == 1 && flag_2 == 1) {
                printf("%d=%d+%d\n", n, i, n - i);
                break;
            }
        }
    }
    return 0;
}
int is_prime(int n){
    int a;
    for (a = 2; a < n; a++) {
        if (n % a == 0) { return 0; }
    }
    if (a == n) { return 1; }
}

8. 实验任务8

#include<stdio.h>
long fun(long s);
int main()
{
    long s, t;
    printf("Enter a number:");
    while (scanf_s("%ld", &s) != EOF) {
        t = fun(s);
        printf("The new number is:%ld\n\n", t);
            printf("Enter a number:");
    }
    return 0;
}
long fun(long s) {
    int a, b=0, i[50]={0};
    int c=0;
    while (s != 0) {
        a = s % 10;
        if (a % 2 != 0) {
            i[b++] = a;
        }
        s /= 10;
    }
    b = b - 1;
    while (b != -1) {
        c = c * 10 + i[b--];
    }
    return c;
}