实验三

 1 #define N 80

void printText(int Line, int col, char text[]);
void printSpaces(int n);
void printBlankLines(int n);

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

    srand(time(0));

    for(i=0;i<=10;i++)
    {
        line = rand()%25;
        col = rand()%80;
        printText(line, col, text);
        Sleep(1000);
    }

    return 0;
}

void printSpaces(int n)
{
    int i;

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

void printBlankLines(int n)
{
    int i;

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

void printText(int line, int col, char text[])
{
    printBlankLines(line-1);
    printSpaces(col-1);
    printf("%s",text);
}

在屏幕十个随机位置每隔1秒打印hi，May#include <stdio.h> 

实验任务2：

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>
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;
}

static变量特性：该变量只可在其被声明的函数中被调用，且再次进入该函数时保存值不变。

实验任务3：

#include<stdio.h>
long long fun(int n);

int main()
{
    int n;
    long long f;

    while(scanf("%d",&n)!=EOF)
    {
        f=fun(n);
        printf("n=%d, f=%lld\n",n,f);
    }

    return 0;
}

long long fun(int n)
{
    long long f;
    int i;

    if(n==1)
        f=1;
    else
        f=2*fun(n-1)+1;

    return f;
}

实验任务4：

#include<stdio.h>
void hanoi(unsigned int n, char from, char temp, char to);
void moveplate(unsigned int n, char from, char to);
int count(int n);
int main()
{
    unsigned int n;
    while (scanf("%u", &n) != 0)
    {
        hanoi(n, 'A', 'B', 'C');
        printf("一共移动了%d次\n\n", count(n));
    }
    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("第%u个盘子:%c-->%c\n", n, from ,to);
}
int count(int n)
{
    int i = 1,s;
    if (n == 1)
        s = 1;
    else
        s = 2 * count(n - 1) + 1;
    return s;
}

实验任务5：

#include <stdio.h>
int Isprime(int n){
int i;
for(i=2;i<=n-1;i++)
{
if(n%i==0) 
return 0;
}
return 1;
}
int main(){
int i,n;
for(n=4;n<=20;n+=2)
{
for(i=2;i<=n/2;i++)
{
if(Isprime(i)*Isprime(n-i)){
printf("%d=%d+%d\n",n,i,n-i);
break;
}
}
}
return 0;
}

#include <stdio.h>
#include<math.h>
long fun(long s);
int main()
{
    long s, t;
    printf("Enter a number: ");
    while (scanf("%ld", &s) != 0)
    {
        t = fun(s); 
        printf("new number is: %ld\n\n", t);
        printf("Enter a number: ");
    }
    return 0;
}
long fun(long s)
{
    long i, j=0,k=0;
    while (s / 10 != 0||s==1)
    {
        i = s % 10;
        if (i % 2 != 0)
        {
            j = i * pow(10,k) + j;
            k++;
        }
        s /= 10;
    }
    return j;
}