C Primer Plus 第6版 第6章 编程练习

#include<stdio.h>
int main()
{
  char array_c[26];
  for (int i = 0; i < 26; i++)
  {
    array_c[i] = 'a' + i;
  }
 
  for (int i = 0; i < 26; i++)
  {
    printf("%c ", array_c[i]);
  }
  getchar();
  return 0;
}

#include<stdio.h>
int main()
{
 
  for (int i = 1; i <= 5; i++)
  {
    for (int j = 1; j <= i; j++)
      printf("$");
    printf("\n");
 
  }
  getchar();
  return 0;
}

#include<stdio.h>
int main()
{
 
  for (int i = 1; i <= 6; i++)
  {
    for (int j = 1; j <= i; j++)
      printf("%c",'F'+1-j);
    printf("\n");
 
  }
  getchar();
  return 0;
}

#include<stdio.h>
int main()
{
  char a = 'A';
  for (int i = 1; i <= 6; i++)
  {
    for (int j = 1; j <= i; j++)
      printf("%c",a++);
    printf("\n");
 
  }
  getchar();
  return 0;
}

#include<stdio.h>
int main()
{
 
  char a = 'A';
  printf("请输入一个大写字母");
  scanf_s("%c", &a);
  for (int i = 1; i <= 5; i++)
  {
    for (int j1 = 1; j1 <= 5 - i; j1++)
      printf(" ");
    for (int j2 = 1; j2 <= i; j2++)
      printf("%c", a + j2-1);
    for (int j3 = 1; j3 <= i - 1; j3++)
      printf("%c", a + i - 1 - j3);
    printf("\n");
  }
  getchar();  getchar();
  return 0;
}

#include<stdio.h>
int main()
{
 
  int min;
  printf("请输入下限");
  scanf_s("%d",&min);
  int max;
  printf("请输入上限");
  scanf_s("%d", &max);
 
  for (int i = min; i <= max; i++)
  {
    printf("%10d %10d %10d\n", i, i*i, i*i*i);
  
  }
  getchar();  getchar();
  return 0;
}

#include<stdio.h>
#include<string.h>
int main()
{
  char word[20];
  printf("请输入单词");
  scanf_s("%s", word,20);
  for (int i = strlen(word)-1; i >= 0; i--) //下标是长度-1
    printf("%c", word[i]);
  getchar();  getchar();
  return 0;
}

#include<stdio.h>
int main()
{
  float a, b;
  printf("请输入两个浮点数");
  while (scanf_s("%f%f",&a,&b))
  {
    printf("(%f-%f)/(%f*%f)=%f\n", a, b, a,b, (a - b) / (a*b));
    printf("请输入两个浮点数");
  }
 
  getchar();  getchar();
  return 0;
}

#include<stdio.h>
int sum(int min, int max)
{
  int sum = 0;
  for (int i = min; i <= max; i++)
  {
    sum += i * i;
  }
  return sum;
}
int main()
{
  int min, max;
  printf("请输入下限和上限");
  while (scanf_s("%d%d",&min,&max) && min < max)
  {
    printf("平方和从%d到%d是 %d\n", min*min,max*max,sum(min,max));
    printf("请输入下限和上限");
  }
  printf("Done");
  getchar();  getchar();
  return 0;
}

#include<stdio.h>
float sum(int n)
{
  float sum = 0.0;
  for (int i = 1; i <= n; i++)
  {
    sum += 1.0 / i;
  }
  return sum;
}
float sum2(int n)
{
  float sum2 = 0.0;
  int aa = 1;
  for (int i = 1; i <= n; i++)
  {
    sum2 += 1.0 / i * aa;
    aa *= -1;
  }
  return sum2;
}
int main()
{ 
  int n = 1;  
  while (n > 0)
  {
    printf("输入项数:");
    scanf_s("%d", &n);
    printf("sum1 = %f,sum2 = %f\n", sum(n), sum2(n));
 
  }
  getchar();  getchar();
  return 0;
}

#include<stdio.h>
#include<math.h>
int main()
{
  int t[8];
  for (int i = 0; i < 8; i++)
  {
    t[i] = pow(2, i);
  }
  int i = 0;
  do
  {
    printf("%d\t", t[i++]);
  } while (i<8);
  getchar();  getchar();
  return 0;
}

#include<stdio.h>
int main(void)
{
  double d[8];
  double dd[8];
  for (int i = 0; i < 8; i++)
  {
    printf("输入第%d个值", i+1);
    scanf_s("%lf", &d[i]);
  }
  dd[0] = d[0];
  for (int i = 1; i < 8; i++)
  {
    dd[i] = dd[i - 1] + d[i];
  }
  for (int i = 0; i < 8; i++)
    printf("%lf ", d[i]);
  printf("\n");
  for (int i = 0; i < 8; i++)
    printf("%lf ", dd[i]);
  printf("\n");
 
  getchar(); getchar();
  return 0;
}

#include<stdio.h>
int main(void)
{
  char sentence[256];
  int i = 0;
  while (scanf_s("%c", &sentence[i]) && sentence[i] != '\n')
    i++;
  int j = i-1;
  while (j >= 0)
    printf("%c", sentence[j--]);
  getchar(); getchar();
  return 0;
}