实验三

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

调用函数控制空格与回车的个数，i控制打印的数组个数

 实验任务2

2.1

#include <stdio.h>
#include<stdlib.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));
system("pause");
return 0;
}
// 函数定义
long long fac(int n) {
static long long p = 1;


p = p * n;

return p;}

 2.2

#include <stdio.h>
#include<stdlib.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));
system("pause");
return 0;
}
// 函数定义
long long fac(int n) {
static long long p = 1;
printf("p = %lld\n", p);

p = p * n;

return p;}

2.3

#include <stdio.h>
#include<stdlib.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);
system("pause");
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

#include <stdio.h>
long long func(int n); // 函数声明
int main() {
int n;
long long f;
while (scanf("%d", &n) != EOF) 
{
f = func(n); // 函数调用
printf("n = %d, f = %lld\n", n, f);
}
return 0;}

long long func(int n)
{
    long long a;

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

实验任务4

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

实验任务5

5.1

#include <stdio.h>
double mypow(int x, int y); // 函数声明
int main() {
int x, y;
double ans;
while(scanf("%d%d", &x, &y) != EOF) {
ans = mypow(x, y); // 函数调用
printf("%d的%d次方: %g\n\n", x, y, ans);
}
return 0;

}
double mypow(int x,int y)
{
    double ans=1.0;
    double t,m;

    if(y>0)
        m=y;
    if(y<0)
        m=-y;

    int i;
    for(i=0;i<m;i++)

        if(y>=0)
            ans*=x;
        else
        {t=x;
    ans*=1/t;}

    return ans;
    

}

 5.2

#include <stdio.h>
double mypow(int x, int y); // 函数声明
int main() {
int x, y;
double ans;
while(scanf("%d%d", &x, &y) != EOF) {
ans = mypow(x, y); // 函数调用
printf("%d的%d次方: %g\n\n", x, y, ans);
}
return 0;

}
double mypow(int x,int y)
{
    double ans=1.0;
    double t;
    int i;

    if(y==0)
        ans=1;

    if(y>0)
        ans=mypow(x,y-1)*x;

    if(y<0)
        ans=1/mypow(x,-y);

    return ans;



}

 实验任务6

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

实验任务7

#include<stdio.h>
int is_prime(int x);
 
int main() {
    int i, n;
    while (scanf("%d", &n) != EOF) {
        for (i = 2; i <= n; i++) {
            if (!is_prime(i) || !is_prime(n - i))continue;
            printf("%d = %d + %d\n", n, i, n - i);
            break;
        }
    }
    return 0;
}
 
int is_prime(int x) {
    int i;
    for (i = 2; i *i<= x; i++) {
        if (x % i == 0) {
            return 0;}
        else {
            return 1; }
    }
}

 实验任务8

#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); // 函数调用
printf("new number is: %ld\n\n", t);
printf("Enter a number: ");
}
return 0;
}
long func(long s) 
{
    long t = 0, t1 = 0;
    while (s > 0) 
    {
        int tmp = s % 10;
        s /= 10;
        if (tmp % 2 == 1)t1 = t1 * 10 + tmp;
    }
    while (t1 > 0) {
        t = t * 10 + (t1 % 10);
        t1 /= 10;
    }
    return t;
}