ural 1255. Graveyard of the Cosa Nostra

 1 /**
 2 Create By yzx - stupidboy
 3 */
 4 #include <cstdio>
 5 #include <cstring>
 6 #include <cstdlib>
 7 #include <cmath>
 8 #include <deque>
 9 #include <vector>
10 #include <queue>
11 #include <iostream>
12 #include <algorithm>
13 #include <map>
14 #include <set>
15 #include <ctime>
16 #include <iomanip>
17 using namespace std;
18 typedef long long LL;
19 typedef double DB;
20 #define MIT (2147483647)
21 #define INF (1000000001)
22 #define MLL (1000000000000000001LL)
23 #define sz(x) ((int) (x).size())
24 #define clr(x, y) memset(x, y, sizeof(x))
25 #define puf push_front
26 #define pub push_back
27 #define pof pop_front
28 #define pob pop_back
29 #define ft first
30 #define sd second
31 #define mk make_pair
32 
33 inline int Getint()
34 {
35     int Ret = 0;
36     char Ch = ‘ ‘;
37     bool Flag = 0;
38     while(!(Ch >= ‘0‘ && Ch <= ‘9‘))
39     {
40         if(Ch == ‘-‘) Flag ^= 1;
41         Ch = getchar();
42     }
43     while(Ch >= ‘0‘ && Ch <= ‘9‘)
44     {
45         Ret = Ret * 10 + Ch - ‘0‘;
46         Ch = getchar();
47     }
48     return Flag ? -Ret : Ret;
49 }
50 
51 int n, k;
52 
53 inline void Input()
54 {
55     cin >> n >> k;
56 }
57 
58 inline void Solve()
59 {
60     if(n < k) cout << 0 << endl;
61     else cout << ((n / k) * n) + ((n % k) * (n / k)) + max(2 * (n % k) - k, 0) << endl;
62 }
63 
64 int main()
65 {
66     freopen("a.in", "r", stdin);
67     Input();
68     Solve();
69     return 0;
70 }