#include<bits/stdc++.h> using namespace std; const int N = 505, SQ = 24; int n, sum, A[N]; bitset < N * N > T, R, B, P[SQ]; int main() { scanf("%d", &n); bool odd = 0, even = 0; for (int i = 0; i < n; i++) { scanf("%d", &A[i]); sum += A[i]; if (A[i] & 1) odd = 1; else even = 1; } if (odd && even) return !printf("0"); if (odd && (n & 1)) return !printf("0"); for (int i = 0; i <= (n - 1) / SQ; i++) { P[i][0] = 1; int l = i * SQ, r = min(l + SQ, n); for (int j = 0; j < n; j++) if (j < l || r <= j) P[i] |= P[i] << A[j]; } B[0] = 1; for (int j = 0; j < n; j++) B |= B << A[j]; if (!B[sum >> 1]) return !printf("0"); for (int j = 1; j < N * N; j++) R[j] = 1; for (int i = 0; i < n; i++) { int block = i / SQ; int l = block * SQ, r = min(l + SQ, n); B = P[block]; for (int j = l; j < r; j++) if (j != i) B |= B << A[j]; int _sum = sum - A[i]; int half = (_sum + 2) >> 1; T = 0; for (int j = half; j <= _sum; j++) if (B[j]) T[j + j - _sum] = 1; R = R & T; } printf("%d\n", (int)R.count()); for (int j = 1; j < N * N; j++) if (R[j]) printf("%d ", j); return 0; }

bootfall.cpp: In function 'int main()':
bootfall.cpp:8:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
bootfall.cpp:12:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &A[i]);
         ~~~~~^~~~~~~~~~~~~