c语言编程求解不等式。

Question

己知不等式1!+2!+……+m!<n,请编程对用户输入的整数n,输出m的取值，

Answer 1

已知不等式 1！+2！+3！+...+m！‹n,请编程对用户指定的n值计算并输出满足该不等式的m的整数解？_360问答 https://m.wenda.so.com/q/1464305105728840

#include <stdio.h>
double digui(int n){    
  if (n == 1 || n == 0)        
    return 1;    
  else        
    return n*digui(n-1);
}
int main(void){     
  int m;     
  double y,n;     
  scanf ("%lf",&n);
  y = 0;    
  for (m = 1;y < n;m++){       
    y = y+digui(m);    
  }     
  printf ("%d\n",m-2);    
  return 0;
}

Answer 2

#include <stdio.h>

int main(int argc, char const *argv[])
{
    long long int a = 0;
    int b = 0, sum = 1;
    scanf("%lld", &a);
    while (a > 0)
    {
        sum = 1;
        b += 1;
        for (int i = 1; i <= b; i++)
        {
            sum *= i;
        }
        a -= sum;
        }
    printf("%d", b-1);
};