poj2006

化学计算题，解一元二次方程

#include<stdio.h>#include<math.h>int main(){  double ka,acid,temp,res;  int m,n;    while(1)  {    scanf("%lf%lf%d%d",&ka,&acid,&m,&n);    if(ka==0&&acid==0&&m==0&&n==0)      break;    temp = (-ka + (double)sqrt(ka*ka+4*n*acid*ka*m))/(2*n);    res=-log10(temp);    printf("%.3lf\n",res);      }  return 0;}