CDZSC_2015寒假新人（2）——数学 - O

 1 #include <cstdio>
 2 #include <cstring>
 3 
 4 const int MAX = 24;
 5 int arr[MAX][MAX];
 6 
 7 int main()
 8 {
 9 #ifdef CDZSC_OFFLINE
10     freopen("in.txt", "r", stdin);
11     freopen("out.txt", "w", stdout);
12 #endif
13     int t, n, sum, ans[MAX];
14     memset(arr, 0, sizeof(arr));
15     memset(ans, 0, sizeof(ans));
16     for(int i = 0; i < MAX; i++)
17     {
18         arr[i][0] = 1;
19         for(int j = 1; j < i; j++)
20         {
21             arr[i][j] = arr[i - 1][j - 1] + arr[i - 1][j];
22         }
23         arr[i][i] = 1;
24     }
25     for(int i = 1; i < MAX; i++)
26     {
27         sum = 0;
28         for(int j = 1; j <= i; j++)
29         {
30             sum += j * arr[i - 1][j - 1];
31         }
32         ans[i] = sum;
33     }
34     scanf("%d", &t);
35     while(t--)
36     {
37         scanf("%d", &n);
38         printf("%d\n", ans[n]);
39     }
40     return 0;
41 }