*********************** 第 1 題 ***********************
//b004: 繩子上吃草的牛 by Snail
#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;
int main () {
double D, L, r1, r2, area, PI=acos(-1.);
while (cin >> D >> L) {
r1 = L / 2; //長軸
r2 = sqrt (L*L - D*D) / 2; //短軸
area = PI * r1 * r2; //area--面積
cout << fixed << setprecision(3) << area << endl;
}
}
*********************** 第 2 題 ***********************
//b080: A. 畢氏定理(NPSC 2007 國中組決賽) by Snail
#include <iostream>
#include <cmath>
using namespace std;
int main () {
int a, b, c, c2; //c2 (c^2)--c 平方
while (cin >> a >> b, a) {
c2 = a*a + b*b; //假設a, b 為兩股
c = (int)sqrt(double(c2));
if (c2 == c*c) //如果a,b,c 是直角三角形
cout << c << endl;
else {
if (a < b) swap (a, b); //確使a 為斜邊
c2 = a*a - b*b;
c = (int)sqrt(double(c2));
if (c2 == c*c) //如果a,b,c 是直角三角形
cout << c << endl;
else
cout << "Wrong\n";
}
}
}
*********************** 第 3 題 ***********************
//b197: B. 下雨天(NPSC 2008 國中組初賽) by Snail
#include <iostream>
#include <cmath>
using namespace std;
int main () {
int n, x1, y1, x2, y2, s, tc, i, mini;
double l, c, minc; //c(ost)--單位雨量的價格
cin >> tc;
while (tc--) {
cin >> n;
minc = 1e100; //min c(ost)--最低價格
for (i=1; i<=n; i++) {
cin >> x1 >> y1 >> x2 >> y2 >> s;
l = sqrt( double((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2)));
c = s * l / abs(x1-x2); //l(ength)--遮雨棚長度
if (c < minc)
mini = i, minc = c; //min i(ndex)--最低價格索引
}
cout << mini << endl;
}
}
*********************** 第 4 題 ***********************
//b226: E. 鋪地磚(NPSC 2008 國中組決賽) by Snail
#include <iostream>
using namespace std;
int main () {
int L, W, x, y;
while (cin >> L >> W >> x >> y, L) {
cout << ((L%x || W%y) && (L%y || W%x) ? -1 : (L * W) / (x * y)) << endl;
} //若直擺不行 橫擺也不行 小屋面積 / 磁磚面積
}
*********************** 第 5 題 ***********************
//11150 - Cola (by Snail)
#include <iostream>
using namespace std;
int main() {
int n;
while (cin >> n)
cout << n * 3 / 2 << endl; //等比級數r = 3
}
*********************** 第 6 題 ***********************
//b225: D. 棒球練習 (NPSC 2008 國中組決賽) by Snail
#include <iostream>
using namespace std;
int main () {
int n, x1, y1, x2, y2, x3, y3;
cin >> n;
while (n--) {
cin >> x1 >> y1 >> x2 >> y2 >> x3 >> y3;
cout << ((x2-x1)*(y3-y1) == (x3-x1)*(y2-y1) ? "NO\n" : "YES\n");
} //若斜率相等則不成一個三角形
}
*********************** 第 7 題 ***********************
//d122: Oh! My Zero!! (by Snail)
#include <iostream>
using namespace std;
int main () {
int n, z;
while (cin >> n) {
z = 0; //z(eros)--零的個數
while (n /= 5)
z += n;
cout << z << endl;
}
}