每个初学者都必须知道的 C 语言编程示例 – 下

#include <stdio.h>
int main()
{
int n, i;
printf("Enter an integer: ");
scanf("%d",&n);
for(i=1; i<=10; ++i)
{
printf("%d * %d = %d \n", n, i, n*i);
}
return 0;
}

#include <stdio.h>
int main()
{
    int i, n, t1 = 0, t2 = 1, nextTerm = 0;
    printf("Enter the number of terms: ");
    scanf("%d",&n);
    // displays the first two terms which is always 0 and 1
    printf("Fibonacci Series: %d, %d, ", t1, t2);
    // i = 3 because the first two terms are already dislpayed
    for (i=3; i <= n; ++i)
    {
        nextTerm = t1 + t2;
        t1 = t2;
        t2 = nextTerm;
        printf("%d, ",nextTerm);
    }
    return 0;
}

#include <stdio.h>
int main()
{
    double number;
    printf("输入一个数字: ");
    scanf("%lf", &number);
    if (number <= 0.0)
    {
        if (number == 0.0)
            printf("您输入了 0。");
        else
            printf("您输入了一个负数。");
    }
    else
        printf("你输入了一个正数。");
    return 0;
}

#include<stdio.h>
#include<string.h>
int main()
{
char str[100],rev[100];
int i,len=0;
printf("请输入字符串");
gets(str);
for(i=0;i<=100;i++)
{
if(str[i]=='\0')
{
break;
}
len++;
}
for(i=0;i<=len-1;i++)
{
rev[i] = str[len-i-1];
}
printf("字符串的反向是 %s",rev);
return 0;
}

#include <stdio.h>
int main()
{
    char c;
    for(c='A'; c<='Z'; ++c)
       printf("%c ",c);
    return 0;
}

#include <stdio.h>
int main()
{
    int n, reversedInteger = 0, remainder, originalInteger;
    printf("Enter an integer: ");
    scanf("%d", &n);
    originalInteger = n;
    // reversed integer is stored in variable  
    while( n!=0 )
    {
        remainder = n%10;
        reversedInteger = reversedInteger*10 + remainder;
        n /= 10;
    }
    // palindrome if orignalInteger and reversedInteger is equal
    if(originalInteger == reversedInteger)
        printf("%d is a palindrome.", originalInteger);
    else
        printf("%d is not a palindrome.", originalInteger);
    return 0;
}

#include <stdio.h>
int main()
{
    int number, originalNumber, remainder, result = 0;
    printf("Enter a three digit integer: ");
    scanf("%d", &number);
    originalNumber = number;
    while (originalNumber != 0)
    {
        remainder = originalNumber%10;
        result += remainder*remainder*remainder;
        originalNumber /= 10;
    }
    if(result == number)
        printf("%d is an Armstrong number.",number);
    else
        printf("%d is not an Armstrong number.",number);
    return 0;
}

#include<stdio.h>
int main() {
   int i, j;
   int num;
   printf("Enter the number of Digits :");
   scanf("%d", &num);
   for (i = 0; i <= num; i++) {
      for (j = 0; j < i; j++) {
         printf("%d ", i);
      }
      printf("\n");
   }
   return 0;
}

#include <stdio.h>
int main()
{
    int n, reversedNumber = 0, remainder;
    printf("Enter an integer: ");
    scanf("%d", &n);
    while(n != 0)
    {
        remainder = n%10;
        reversedNumber = reversedNumber*10 + remainder;
        n /= 10;
    }
    printf("Reversed Number = %d",reversedNumber);
    return 0;
}

#include <stdio.h>
int main()
{
      double firstNumber, secondNumber, temporaryVariable;
      printf("Enter first number: ");
      scanf("%lf", &firstNumber);
      printf("Enter second number: ");
      scanf("%lf",&secondNumber);
      // Value of firstNumber is assigned to temporaryVariable
      temporaryVariable = firstNumber;
      // Value of secondNumber is assigned to firstNumber
      firstNumber = secondNumber;
      // Value of temporaryVariable (which contains the initial value of firstNumber) is assigned to secondNumber
      secondNumber = temporaryVariable;
      printf("\nAfter swapping, firstNumber = %.2lf\n", firstNumber);
      printf("After swapping, secondNumber = %.2lf", secondNumber);
      return 0;
}