task1_1

#include<stdio.h>
#include<stdlib.h>
long long fac(int n);
int main()
{
    int i,n;
    printf("Enter n:");
    scanf("%d",&n);
    for (i=1;i<=n;++i)
     printf("%di=%lld\n",i ,fac(i));
    system("pause");
    return 0;
}
long long fac(int n){
    static long long p=1;

    p=p * n;
    return p;
}

 

 

#include<stdio.h>
#include<stdlib.h>
long long fac(int n);
int main()
{
    int i,n;
    printf("Enter n:");
    scanf("%d",&n);
    for (i=1;i<=n;++i)
     printf("%di=%lld\n",i ,fac(i));
    system("pause");
    return 0;
}
long long fac(int n){
    static long long p=1;
    printf("p=%lld\n",p);
    p=p * n;
    return p;
}

 

 

 

task1_2

#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);
}

 

 

task2

 迭代

#include<stdio.h>
#include<stdlib.h>
void printSymbol(int n, char symbol);
int main() {
    int n;
    char symbol;
    while (scanf("%d %c", &n, &symbol) != EOF) {
        printSymbol(n, symbol);
        printf("\n");
    }
    system("pause");
    return 0;
}
void printSymbol(int n, char symbol) {
   while(n--)
        printf("%c", symbol);
}

 递归

#include<stdio.h>
#include<stdlib.h>
void printSymbol(int n, char symbol);
int main() {
    int n;
    char symbol;
    while (scanf("%d %c", &n, &symbol) != EOF) {
        printSymbol(n, symbol);
        printf("\n");
    }
    system("pause");
    return 0;
}
void printSymbol(int n, char symbol) {
  if(n==1)
        printf("%c", symbol);
  else {
      printf("%c", symbol);
      printSymbol(n - 1, symbol);
  }

 

 

 

task3

#include<stdio.h>
#include<stdlib.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);
        }
    system("pause");
    return 0;
}
long long fun(int n){
     unsigned int z;
    if(n ==1)
        z=2;
    else
        z=2 *(fun(n-1)+1);
    z=z-1;
    return z;
}

 

 

 

 

 

task4

#include<stdio.h>
#include<math.h>
#include<stdlib.h>
long long isPrime(int n);
int main()
{
    int i,s=0;
    for(i=101;i<201;i++){
        if(isPrime(i)==1)
            {printf("%d ",i);
             s++;
            }
        if(s%10==0)
            printf("\n");
    }
    printf("\n");
    printf("101~200之间一共有%d个非整数",s);
    system("pause");
    return 0;
}
long long isPrime(int n){
      int z,j;
      for(j=15;j>0;j--){
          if(n%j==0)
              break;}
      if(j==1)
          z=0;
      else
          z=1;    
    return z;
}

 

 

task5

 

#include <stdio.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 i=1,j,a,b=0 ;
    do {
        a = s % 10;
        s = s / 10;
        if (a % 2 != 0) {
            b = b + i * a;
            i = 10 * i;
        }
    } while (s != 0);
        return b;
    }

task6

#include <stdio.h>
double fun(int n);
long long fac(int n);
int main() {
    int n;
    double s;
    printf("Enter n(1~10): ");
    while (scanf("%d", &n) != EOF) {
        s = fun(n);
        printf("n= %d, s=%f  \n", n, s);
        printf("Enter n(1~10): ");
    }
    return 0;
}
double fun(int n) {
     long double r = 0;
    int i;
    for (i = 1; i <= n; i++) {
        r = r + 1.0 / fac(i);
    }
    return r;
    }
long long fac(int n) {
     long long p=1 ;
     int i;
     for (i = 1; i <= n; i++)
         p = p * i;
    if (n % 2 == 0)
        p = (-1)*p;
    return p;
}