UESTC 2014 Summer Training #5 Div.2

 1 #include <map>
 2 #include <set>
 3 #include <cmath>
 4 #include <ctime>
 5 #include <queue>
 6 #include <stack>
 7 #include <cstdio>
 8 #include <iomanip>
 9 #include <string>
10 #include <vector>
11 #include <cstring>
12 #include <sstream>
13 #include <iostream>
14 #include <fstream>
15 #include <algorithm>
16 #include <bitset>
17 #include <climits>
18 #include <ostream>
19 #include <ios>
20 #include <cstdlib>
21 using namespace std;
22 
23 #define wh while
24 #define inf (int)(~0u/2)
25 #define FOR(i, n) for(int i = 0; i < n; i++)
26 #define FOR1(i, n) for(int i = 1; i < n; i++)
27 #define FOR2(i, n) for(int i = 0; i <= n; i++)
28 #define REP(i,n) for(int i = 1; i <= n; i++)
29 #define FORI(it,n) for(typeof(n.begin()) it = n.begin(); it != n.end(); it++)
30 #define sf scanf
31 #define pf printf
32 #define frs first
33 #define sec second
34 #define psh push_back
35 #define mkp make_pair
36 #define PB(x) push_back(x)
37 #define MP(x, y) make_pair(x, y)
38 #define clr(abc,z) memset(abc,z,sizeof(abc))
39 #define lt(v) v << 1
40 #define rt(v) v << 1 | 1
41 #define mid ((l + r) >> 1)
42 #define lson l, mid, v << 1
43 #define rson mid + 1, r, v << 1 | 1
44 
45 #define fre freopen("1.txt", "r", stdin)
46 
47 typedef long long LL;
48 typedef long double LD;
49 const double eps = 1e-8;
50 
51 double area(double x, double y, double z){
52     double p = (x + y + z) / 2;
53     return (z * z / 4.0 + sqrt(p * (p - x) * (p - y) * (p - z)));
54 }
55 
56 int main(){
57     double x, y;
58     sf("%lf%lf", &x, &y);
59     double l = 0.0, r = x + y;
60     double md;
61     wh(fabs(r - l) > eps){
62         md = (l + r) / 2;
63         double mdl = (md + l) / 2;
64         double mdr = (md + r) / 2;
65         double v1 = area(x, y, mdl), v2 = area(x, y, mdr);
66         if(v1 > v2)
67             r = (md + r) / 2;
68         else
69             l = (md + l) / 2;
70     }
71     pf("%lf", area(x, y, md));
72 }

1 int main(){
2     int a, b;
3     sf("%d%d", &a, &b);
4     pf("%lf\n", (a * a + b * b + 2 * sqrt(2) * a * b) / 4.0);
5     return 0;
6 }