HDU 2529.Shot

题目:http://acm.hdu.edu.cn/showproblem.php?pid=2529

AC代码(C++):

#include <iostream>#include <queue>#include <string>#include <algorithm>#define INF 0x3f3f3f3f#define eps 1e-8using namespace std;double h, l, v;const double g = 9.8;int main() {    while (cin >> h >> l >> v) {        if (h == 0 && l == 0 && v == 0)break;        double a, b, c;        a = c = -(g*l*l) / (2 * v*v);        b = l;        double ans = 4 * a*c - b*b;        ans /= 4 * a;        ans += h;        printf("%.2lf\n", ans);    }    //system("pause");}

总结: 用物理加速度位移公式做, 不过要把vx和vy表示成vcosθ和vsinθ, 最后才能转换成二次函数形式.