zoj 1096 Subway

#include <stdio.h>#include <math.h>double GetMinTime(int d, int m, int a, int j){    double t1, t2, t3;    t1 = pow(d*0.5/j, 1.0/3.0);    if(j * t1 <= a && j * t1 * t1 <= m)    {        return t1 * 4;    }    t1 = sqrt(m*1.0/j);    if(j*t1 <= a && m*t1*2 <= d)    {        t2 = d*1.0/m - t1*2;        return t1 * 4 + t2;    }    t1 = a*1.0/j;    double aa = a;    double bb = a*a*3.0/j;    double cc = a*a*a*2.0/(j*j) - d;    t3 = (sqrt(bb*bb - 4*aa*cc) - bb)/(aa*2);    double vmax = a*a*1.0/j + a*t3;    if(t3 >= 0 && vmax <= m)    {        return t1 * 4 + t3 * 2;    }    t3 = m*1.0/a - a*1.0/j;    t2 = d*1.0/m - (t1*2 + t3);    return t1 * 4 + t3 * 2 + t2;}int main(int argc, char* argv[]){    double time;    int d, m, a, j;    while(scanf("%d %d %d %d", &d, &m, &a, &j) != EOF)    {        time = GetMinTime(d, m, a, j);        time = ((int)(time*10 + 0.5)) * 0.1;         printf("%.01fn", time);    }    return 0;}