实验三

task1 code

include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <windows.h>
#define N 80

void print_text(int line, int col, char text[]); // 函数声明
void print_spaces(int n); // 函数声明
void print_blank_lines(int n); // 函数声明

int main() {
    int line, col, i;
    char text[N] = "hi, November~";

    srand(time(0)); // 以当前系统时间作为随机种子

    for (i = 1; i <= 10; ++i) {
        line = rand() % 25;
        col = rand() % 80;
        print_text(line, col, text);
        Sleep(1000); // 暂停1000ms
    }

    return 0;
}

// 打印n个空格
void print_spaces(int n) {
    int i;

    for (i = 1; i <= n; ++i)
        printf(" ");
}

// 打印n行空白行
void print_blank_lines(int n) {
    int i;

    for (i = 1; i <= n; ++i)
        printf("\n");
}

// 在第line行第col列打印一段文本
void print_text(int line, int col, char text[]) {
    print_blank_lines(line - 1); // 打印(line-1)行空行
    print_spaces(col - 1); // 打印(col-1)列空格
    printf("%s", text); // 在第line行、col列输出text中字符串
}

task1 result

描述：随机空出一定空格或行，打印hi, November

task2_1code

#include <stdio.h>
long long fac(int n); // 函数声明

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;
}
// 函数定义
long long fac(int n) {
    static long long p = 1;
    p = p * n;

    return p;
}

task2_1 result

task2_2 code

#include <stdio.h>
int func(int, int); // 函数声明
int main() {
    int k = 4, m = 1, p1, p2;
    p1 = func(k, m); // 函数调用
    p2 = func(k, m); // 函数调用
    printf("%d, %d\n", p1, p2);
    return 0;
}
// 函数定义
int func(int a, int b) {
    static int m = 0, i = 2;
    i += m + 1;
    m = i + a + b;
    return m;
}

task2_2 result

总结：static变量只会初始化一次，之后不会初始化。

task3 code

#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;
}

task3 result

task4 code1迭代

#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) {
    int up = 1, down1 = 1, down2 = 1;
    int i;
    int ans;

    if (n < m)
        return 0;
    else {
        for (i = 1; i <= n; i++)
            up *= i;
        for (i = 1; i <= m; i++)
            down1 *= i;
        for (i = 1; i <= (n - m); i++)
            down2 *= i;
        return up / (down1 * down2);
    }
}

code1 result

code2递归

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

code2 result

task5 code

#include<stdio.h>

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

    return 0;
}

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

task5 result

 

task code

#include <stdio.h>
#include <math.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: ");
    }

    return 0;
}

long func(long s) {
    int i = 1;
    int ans = 0;

    while (s > 0) {
        if ((s % 10) % 2 != 0) {
            ans = ans + (s % 10) * i;
            i *= 10;
            s /= 10;
        }
        else
            s /= 10;
    }

    return ans;
}

task6 result