实验任务三

实验任务1

#include<stdio.h>

#include<stdlib.h>

#include<time.h>

#include<windows.h>

#define N 80

 

void print_text(int line, int col, char text[]);

void print_spaces(int n);

void print_blank_lines(int n);

 

int main(void) {

    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;

}

//print n blanks

void print_spaces(int n) {

    int i;

    for (i = 1; i <= n; ++i)

         printf_s(" ");

}

//print n blank lines

void print_blank_lines(int n) {

    int i;

 

    for (i = 1; i <= n; ++i)

         printf_s("\n");

}

//print a text at ""line and ""row

void print_text(int line, int col, char text[]) {

    print_blank_lines(line - 1);

    print_spaces(col - 1);

    printf_s("%s", text);

}

作用：以时间为种子，随机在m行n列生成一个“hi，November”的文本

实验任务2.1

#include<stdio.h>

#include<stdlib.h>

 

long long fac(int n);

 

int main(void) {

    int i, n;

 

    printf_s("Enter n:");

    scanf_s("%d",&n);

 

    for (i = 1; i <= n; ++i)

         printf_s("%d!=%lld\n", i, fac(i));

 

    return 0;

}

//define a function

long long fac(int n) {

    static long long p = 1;

    p *= n;

 

    return p;

}

 

 

 

实验任务2.2

#include<stdio.h>

 

int func(int, int);

 

int main(void) {

    int k = 4, m = 1, p1, p2;

//use a function

    p1 = func(k, m);

    p2 = func(k, m);

    printf_s("%d,%d\n", p1, p2);

 

    return 0;

}

//define a function

int func(int a, int b) {

    static int m = 0, i = 2;

 

    i += m + 1;

    m = i + a + b;

 

    return m;

}

 

 

 

Static变量特性：只初始化一次，后面的结果保持为上一次运行的结果

实验任务3

#include<stdio.h>

long long func(int n);

 

int main(void) {

    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) {

    long long ans=1;

    if (n > 1) { ans = func(n - 1) * 2 + 1; }

    return ans;

 

 

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) {

    int ans=1;

    if (n < m) { ans = 0; }

    else if (m == 0 || m == n) { ans = 1; }

         else ans = func(n - 1, m) + func(n - 1, m - 1);

 

    return ans;

}

 

 

 

 

实验任务5

#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) {

    int mid = 0,ans=0;

    if (n < m) { mid = n, n = m, m = mid; }//保证n为大数

    if (m == 1) { ans = n; }

    if (m != 0 && n != 0) {

         ans =n+mul(n, m - 1);

    }

    else return 0;

   

    return ans;

}

 

 

 

实验任务6

#include <stdlib.h>

#include <stdio.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; int count = 0;

    while (scanf_s("%u", &n) != EOF){

         hanoi(n, 'A', 'B', 'C');

         count = pow(2, n) - 1;

         printf("\n一共移动了%d次\n",count);

    }

    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);

}

 

 

 

实验任务7

#include<stdio.h>

#include<stdlib.h>

#include<math.h>

int is_prime(int n);

 

int main() {

    int oushu = 4; int n1=2, n2=2;

 

    while (oushu<20 ) {

         for (n1=2;n1<oushu;n1++) {

             n2 = oushu - n1;

             if (is_prime(n1) && is_prime(n2)) { printf("%d = %d + %d\n", oushu, n1, n2); break; }

         }

         oushu += 2;

    }

   

   

    return 0;

}

 

int is_prime(int n) {

    int i = 2;

    for (i=2; i <= sqrt(n * 1.0); i++) {

         if (n % i == 0) { break; }

    }

    if (i > sqrt(n * 1.0)&&n!=1)return 1;

    else return 0;

}

 

 

 

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("new number is : %ld\n\n", t);

         printf("Enter a number:");

    }

    return 0;

}

 

long fun(long s) {

    long b; b = s;

    int ans=0 ; int mid=0;

    mid = s % 10;

    if (b != 0) {

         if (mid % 2 == 1) { ans = mid + fun(s / 10) * 10; }

         else ans = fun(s / 10);

    }

 

    return ans;

}