实验三 函数应用编程

实验任务一

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);
}

程序功能:在屏幕上输出“hi,November~”做出动画效果

实验任务二

task2_1.c

#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;
    p = p * n;
    return p;
}

#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_2.c

#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;
}

实验运行结果与我理论分析得到的结果一致

局部static变量在函数内作定义说明，作用仅限于函数内部，保存变量被修改后的值，且变量不会在下一次的循环中被初始化

实验任务三

task3.c

 

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

实验任务四

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

实验任务五

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

实验任务六

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

实验任务七

#include <stdio.h>
int is_prime(int n);
int main()
{    int num, f;
    int stop = 0;
    int i = 2;
    while (i < 20)
    {   i += 2;
        for (int k = 2; k < i;k++)
        {   num = i - k;
            f = is_prime(num);
            if (f)
            {printf("%d = %d + %d\n", i, k, num);
             stop = 1;}
            if (stop) break; }
        stop = 0;}
 return 0;
}
int is_prime(int n)
{if (n == 1) return 0;

    for (int i = 2;i < n;i++)
    {
        int stop = 0;
        if (n % i == 0)
        {return 0;
         stop = 1;
        }
        if (n == 2 || (n % i != 0 && i == n - 1)) return 1;
        if (stop) break;}
}

实验任务八

#include <stdio.h>
#include <math.h>

long fun(long s);

int main() {
    long s, t;

    printf("Enter a number: ");

    while (scanf("%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;
    int i = 0;
    int count = 0;
    while (s != 0)
    {
        n = s % 10;
        if (n % 2 != 0)
        {
           i = n * pow(10, count) + i;
            count++;
        }
        s = s / 10;
    }
    return i;
}