Codeforces Round #230 (Div. 1) 解题报告

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstdlib>
 4 #include <cmath>
 5 #include <cstring>
 6 #include <algorithm>
 7 #include <queue>
 8 #include <stack>
 9 #include <vector>
10 #include <set>
11 #include <map>
12 #define MP(a, b) make_pair(a, b)
13 #define PB(a) push_back(a)
14 
15 using namespace std;
16 
17 typedef long long ll;
18 typedef pair<int ,int> pii;
19 typedef pair<unsigned int, unsigned int> puu;
20 typedef pair<int ,double> pid;
21 typedef pair<ll, int> pli;
22 typedef pair<int, ll> pil;
23 
24 const int INF = 0x3f3f3f3f;
25 const double eps = 1e-6;
26 
27 int main()
28 {
29 //    freopen("in.txt", "r", stdin);
30 
31     ll n, sum;
32     while(cin >> n){
33         if(!n) {
34             cout << 1 << endl;
35             continue;
36         }
37         ll loc = n;
38         sum = 1;
39         for(int i=1; i<n; i++){
40             ll x = n*n - (ll)i*i;
41             double y = sqrt(x);
42             sum += (loc - (ll)y);
43             if((loc - (ll)y)==0) sum++;
44             loc = (ll)y;
45          }
46          sum += (loc-1);
47         cout << 4*sum << endl;
48     }
49     return 0;
50 }