blob: 9f05b2cbc8ad2327f7bea039fb0f5b0dcfb20996 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
|
/*
ID: mytbk921
LANG: C
TASK: subset
*/
#include <stdio.h>
#include <stdlib.h>
int main()
{
FILE *fin = fopen("subset.in", "r");
FILE *fout = fopen("subset.out", "w");
long long dp[40][500];
int N, sum;
int i, j;
fscanf(fin, "%d", &N);
fclose(fin);
sum = N*(N+1)/2;
if (sum%2) {
fprintf(fout, "0\n");
fclose(fout);
return 0;
}
sum /= 2;
/* dp[x][y]: number of sets that sum of set is y
* with all numbers in the set <=x
*
* dp[k][0] = 1
* dp[0][k] = 0 for k>0
*/
for (i=0; i<=N; i++)
dp[i][0] = 1;
for (i=1; i<=sum; i++)
dp[0][i] = 0;
for (i=1; i<=N; i++) {
for (j=1; j<=sum; j++) {
if (j<i)
dp[i][j] = dp[j][j];
else
dp[i][j] = dp[i-1][j] + dp[i-1][j-i];
}
}
fprintf(fout, "%lld\n", dp[N][sum]/2);
fclose(fout);
return 0;
}
|
