c语言第八天

计算1/1-1/2+1/3-1/4+1/5......+1/99-1/100的值

#include<stdio.h>
int main()
{
  int i = 0;
  double sum = 0.0;
  int flag = 1;
  for (i = 1; i <= 100; i++)
  {
    sum = sum + flag * 1.0/ i;
    flag = -flag;
  }
  printf("%lf\n", sum);
  return 0;
}

打印99乘法表

#include<stdio.h>
int main()
{
  int i = 0;
  for (i = 1; i <= 9; i++)
  {
    int j = 1;
    for (j = 1; j <= i; j++)
    {
      printf("%d*%d=%2d ", i, j, i * j);
    }
    printf("\n");
  }
  return 0;
}