leetcode-go/bailian/2755.magic-pocket/main.cc

#include <cstdio>
#include <cstring>

using namespace std;

const int N = 20, V = 40;

int n, a[N], dp[N + 1][V + 1];

int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", &a[i]);
  memset(dp, 0, sizeof(dp));
  // dp[i][j] = dp[i - 1][j - a[i]] + dp[i - 1][j]
  dp[0][0] = 1;
  for (int i = 1; i <= n; i++) {
    dp[i][0] = 1;
    for (int j = 1; j <= V; j++) {
      if (a[i - 1] <= j) dp[i][j] = dp[i - 1][j - a[i - 1]] + dp[i - 1][j];
      else dp[i][j] = dp[i - 1][j];
    }
  }
  printf("%d\n", dp[n][V]);
  return 0;
}